A376827 → D

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Submission text ?

Triangle begins:
  0:     0;
  1:     1;
  2:     6,      6;
  3:    21,     42,     21;
  4:    76,    228,    228,      76;
  5:   255,   1020,   1530,    1020,     255;
  6:   846,   4230,   8460,    8460,    4230,     846;
  7:  2751,  16506,  41265,   55020,   41265,   16506,   2751;
  8:  8856,  61992, 185976,  309960,  309960,  185976,  61992,   8856;
  9: 28251, 226008, 791028, 1582056, 1977570, 1582056, 791028, 226008, 28251;

The row polynomials satisfy (n^2-3*n+2)*P(n,x) = (3*n^2-6*n+3+(6*n^2-12*n+6)*x+(3*n^2-6*n+3)*x^2)*P(n-2,x) + (2*n^2-5*n+2+(2*n^2-5*n+2)*x)*P(n-1,x) for n >= 3, with P(0,x) = 0, P(1,x) = 1, P(2,x) = 6 + 6*x.

P[0, x_] := 0;
P[1, x_] := 1;
P[2, x_] := 6 + 6*x;
P[n_, x_] := P[n, x] = Expand[Together[((3*n^2 - 6*n + 3 + (6*n^2 - 12*n + 6)*x + (3*n^2 - 6*n + 3)*x^2)*P[n - 2, x] + (2*n^2 - 5*n + 2 + (2*n^2 - 5*n + 2)*x)*P[n - 1, x])/(n^2 - 3*n + 2)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten

P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = 1; v[3] = 6 + 6*x; for(n = 3, N, my(i = n + 1); v[i] = ((3*n^2 - 6*n + 3 + (6*n^2 - 12*n + 6)*x + (3*n^2 - 6*n + 3)*x^2)*v[i - 2] + (2*n^2 - 5*n + 2 + (2*n^2 - 5*n + 2)*x)*v[i - 1])/(n^2 - 3*n + 2)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i - 1, v[i])))};
T(9)

Properties

• Real-rooted? Every row P_n, n ≥ 0, is zero or real-rooted with all roots in (−∞, 0]
  by Laguerre’s theorem on differential operators
• Coefficients of one sign? Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
  derived from Laguerre’s theorem on differential operators
• Hadamard kernel (Malo)? Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
  derived from Laguerre’s theorem on differential operators

Proof chains ? JSON

• Laguerre’s theorem on differential operators [SP14] polytool ? step ›

  • from T(n, k) = binomial(n, k)*hypergeom([(1 - n)/2, -n/2], [1], 4).?
    • Row-hypergeometric rows (multiplier sequences) [SP14; Bra15, Thm 7.1 of arXiv:1410.6601] polytool RealRooted RealRooted.isPFMultiplierSequence_eval_of_roots_nonpos RealRooted RealRooted.isPFMultiplierSequence_inv_ascPochhammer RealRooted RealRooted.IsPFMultiplierSequence.mul ? step › direct check
    • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

      • from T(n, k) = binomial(n, k)*hypergeom([(1 - n)/2, -n/2], [1], 4).?
        • ↑ Row-hypergeometric rows (multiplier sequences) (above)

Related ?

Same fingerprint ?

• A178822 → basis A013609
• A028326: Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).
• A178821 → D
• A356546: Triangle read by rows. T(n, k) = RisingFactorial(n + 1, n) / (k! * (n - k)!).
• A129186 → basis A007318
• A038338 → D
• A085880: Triangle T(n,k) read by rows: multiply row n of Pascal's triangle (A007318) by the n-th Catalan number (A00010…
• A131431 → x ↦ x+1 → basis A013609
• A085880 → x ↦ x+1 → basis A013610
• basis-map coefficients of A113214, shifted → D
• A038221 → x ↦ x+1 → basis A013610
• veronese parent of Triangle T(n,k) with diagonals T(n,n-k) = binomial(n,3k).
• A156992 → basis A013609 → D
• A124860: A Jacobsthal-Pascal triangle.
• A356546 → basis A013609
• A178820 → basis A013609
• A178821 → basis A007318 → basis A013610
• basis-map coefficients of Riordan array (1+2x,x(1+x)). shifted by x -> -x + 0
• basis-map coefficients of A127647 → D
• A237765: Triangular array read by rows: T(n,k) = binomial(n,2)*binomial(n,k), n>=0, 0<=k<=n.
• A178822: Triangle read by rows: T(n,k) = C(n+5,5) * C(n,k), 0 <= k <= n.
• A135838 → D
• A135065 → x ↦ x+1 → basis A013610
• A132440 → θ+1 → x ↦ x+1
• A134309 → basis A007318
• basis-map coefficients of A112227 → θ+1 → x ↦ x+1
• A178821: Triangle read by rows: T(n,k) = binomial(n+4,4) * binomial(n,k), 0 <= k <= n.
• A196347 → basis A013609 → D
• A127773 → θ+1 → x ↦ x+1
• A135089 → basis A013609
• A038325: Triangle read by rows whose (i,j)-th entry is binomial(i,j)*11^(i-j)*11^j.
• basis-map coefficients of A113214, shifted → x ↦ x+1 → basis A013610
• basis-map coefficients of A113214, shifted → basis A013609 → D
• A156992 → D
• A038208: Triangle whose (i,j)-th entry is binomial(i,j)*2^i.
• A196347 → basis A013609
• basis-map coefficients of A021012 → x ↦ x+1
• basis-map coefficients of A113214, shifted → basis A013609
• veronese parent of Binomial coefficients C(n,k) with n-k odd, read by rows.
• A131431 → (θ+1)² → x ↦ x+1
• A094305 → basis A013609
• A085880 → D → basis A013609
• A027465 → D → basis A013611
• A156992 → basis A013609
• A028326 → basis A013609 → basis A013609
• image under θ+1 → x ↦ x+1
• A178820 → D
• A178822 → x ↦ x+1 → basis A013610
• A038330 → basis A013611 → basis A013609
• A219570: Triangular array read by rows. T(n,k) is the number of necklaces (turning over is not allowed) of n labeled b…
• A178822 → basis A013609 → D
• A038338 → x ↦ x+1 → basis A013610
• A120910 → basis A013610 → D
• A003506 → D → D
• A127648 → (θ+1)² → x ↦ x+1
• A038338 → basis A013609 → basis A013609
• A196347 → x ↦ x+1 → basis A013610
• A135089 → D
• A156992 → basis A007318 → basis A013610
• Second weight array of Pascal's triangle (formatted as a rectangle), by antidiagonals.
• A156992: Triangle T(n,k) = n!*binomial(n-1, k-1) for 1 <= k <= n, read by rows.
• A356546 → basis A013609 → D
• A134059 → D
• Riordan array (1-x,x/(1-x)).
• A038221 → D
• A038325 → basis A013609 → basis A013609
• A027465 → basis A013611
• A120910 → basis A013610
• A376827: T(n, k) = binomial(n, k)*hypergeom([(1 - n)/2, -n/2], [1], 4).
• basis-map coefficients of A112227 → x ↦ x+1 → basis A013609
• A038208 → D → D
• A038330 → basis A013611 → D
• A196347 → D
• A085881 → basis A013609 → D
• basis-map coefficients of A030528, shifted → (θ+1)² → x ↦ x+1
• A007318: Binomial
• A028326 → basis A007318 → basis A013610
• A178820 → basis A013609 → basis A013609
• A120910 → basis A007318 → basis A013611
• A003506 → basis A013609
• A135838: Triangle read by rows: T(n,k) = 2^floor(n/2)*binomial(n-1,k-1).
• basis-map coefficients of A026729, shifted → basis A007318 → basis A013609
• A134346: Triangle read by rows: T(n,k) = (2^(n+1)-1)*binomial(n,k).
• A085880 → basis A013609
• A258758 → basis A013609
• A136572 → (θ+1)² → basis A007318
• basis-map coefficients of A026729 → (θ+1)² → basis A007318
• A344565 → basis A013609
• A129533: Array read by antidiagonals: T(n,k) = binomial(n+1,2)*binomial(n+k,n+1) for 0 <= k <= n.
• basis-map coefficients of A030528, shifted → θ+1 → basis A007318
• A356546 → basis A013609 → basis A013609
• basis-map coefficients of A112227 → (θ+1)² → basis A007318
• A007318 → ×(−(1/2)n+(1/2)n²) → D
• A003506 → D → basis A013609
• A038279 → basis A013610 → basis A013611
• A131431 → x ↦ x+1
• A134059 → basis A013609
• A134346 → basis A013609
• A178821 → basis A013609
• A085880 → basis A013609 → D
• A038325 → basis A007318 → basis A013610
• A038221 → basis A013609
• basis-map coefficients of A026729, shifted → basis A007318
• A130123 → θ+1 → basis A007318
• A135065: A127733 * A007318 as infinite lower triangular matrices.
• basis-map coefficients of A026729 → basis A007318 → basis A013609
• A196347 → basis A013609 → basis A013609
• veronese parent of Binomial coefficients C(n,k) with n-k even, read by rows.
• A135065 → D
• A085881: Triangle T(n,k) read by rows: multiply row n of Pascal's triangle (A007318) by A001147(n).
• A178820 → basis A013609 → D
• A380114: Triangle read by rows: The convolution triangle of 2^n, where the convolution triangle of a sequence is define…
• A038325 → basis A013609
• veronese parent of Triangle T(n,k) with diagonals T(n,n-k) = binomial(n,3k).
• basis-map coefficients of A026729, shifted → θ+1 → x ↦ x+1
• A028326 → D
• A216973: Exponential Riordan array [x*exp(x),x].
• A038208 → D → basis A013609
• A127952: Triangle read by rows, T(n,k) = (n+1)*binomial(n-1,k-1).
• A038325 → basis A013609 → D
• A127773 → (θ+1)² → x ↦ x+1
• basis-map coefficients of A112227 → x ↦ x+1
• A178822 → D
• A376827 → basis A013609
• A178820: Triangle read by rows: T(n,k) = C(n+3,3) * C(n,k), 0 <= k <= n.
• A038338 → basis A013609
• A178821 → basis A013609 → D
• A156992 → basis A013609 → basis A013609
• A356546 → x ↦ x+1 → basis A013610
• A178821 → basis A013609 → basis A013609
• A028326 → basis A013609 → D
• A131431 → x ↦ x+1 → D
• A134058: Triangle T(n, k) = 2*binomial(n, k) with T(0, 0) = 1, read by rows.
• A038325 → D
• A038221 → basis A013609 → D
• A038330 → basis A013611
• A344565: Triangle read by rows, for 0 <= k <= n: T(n, k) = binomial(n, k) * binomial(binomial(n + 3, 2), 2).
• image under θ+1 → (θ+1)² → x ↦ x+1
• A085880 → D
• A097805: Number of compositions of n with k parts, T(n, k) = binomial(n-1, k-1) for n, k >= 1 and T(n, 0) = 0^n, triang…
• A135065 → basis A013609
• basis-map coefficients of A026729 → D → basis A007318
• A178820 → basis A007318 → basis A013610
• basis-map coefficients of A113214, shifted → D → basis A013609
• Hadamard-factor parent of A127773 → x ↦ x+1
• A344565 → D
• A027465 → basis A013611 → D
• basis-map coefficients of A026729 → basis A007318
• A124860 → D
• A132200: Numbers in (4,4)-Pascal triangle .
• Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*12^j.
• A094305 → x ↦ x+1 → basis A013610
• A085881 → D
• basis-map coefficients of A127647 → basis A013609
• A085880 → D → D
• A258758: Triangle T(n,k) = C(n+k-1,k)*C(2*n-1,n-k).
• A134346 → D
• A027465 → basis A013611 → basis A013609
• A028326 → basis A013609
• basis-map coefficients of A026729, shifted → (θ+1)² → basis A007318
• A135089: Triangle T(n,k) = 5*binomial(n,k) with T(0,0) = 1, read by rows.
• basis-map coefficients of A113214, shifted → basis A013609 → basis A013609
• A124860 → basis A013609
• basis-map coefficients of A113214, shifted → D → D
• basis-map coefficients of A026729, shifted → D → basis A007318
• A258758 → D
• A038208 → D
• A085880 → basis A013609 → basis A013609
• A132200 → basis A013609
• A094305: Triangle read by rows: T(n,k) = ((n+1)(n+2)/2) * binomial(n,k) (0 <= k <= n).
• A003506: Triangle of denominators in Leibniz's Harmonic Triangle a(n,k), n >= 1, 1 <= k <= n.
• A094305 → D
• A028326 → D → D
• A003506 → x ↦ x+1 → basis A013610
• A120910 → basis A013610 → basis A013609
• A134058 → basis A013609
• A356546 → D
• A196347: Triangle T(n, k) read by rows, T(n, k) = n!*binomial(n, k).
• A085881 → basis A007318 → basis A013610
• A003506 → D
• A038221: Triangle whose (i,j)-th entry is binomial(i,j)*3^(i-j)*3^j.
• basis-map coefficients of Triangle read by rows: row n consists of n-1 zeros followed by Fibonacci(n).
• A178822 → basis A013609 → basis A013609
• A085881 → basis A013609 → basis A013609
• A135838 → basis A013609
• basis-map coefficients of A021012 → θ+1 → basis A007318
• A132200 → D
• A131431 → θ+1 → basis A007318
• A085881 → basis A013609
• A134059: Triangle T(n, k) = 3*binomial(n,k) with T(0, 0) = 1, read by rows.
• veronese parent of Triangle T(n,k) with diagonals T(n,n-k) = binomial(n,3k).
• A038338 → basis A013609 → D

References

1. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
2. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.