A344565 → γ

OEIS matches ?

• A050534: row sums, 15 terms agree OEIS nonn (row-sum match: finite agreement only) · view at the OEIS

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

Triangle begins:
  0:    3;
  1:   15;
  2:   45;
  3:  105;
  4:  210;
  5:  378;
  6:  630;
  7:  990;
  8: 1485;
  9: 2145;

The row polynomials satisfy -n*P(n,x) = -(n+4)*P(n-1,x) for n >= 1, with P(0,x) = 3.

P[0, x_] := 3;
P[n_, x_] := P[n, x] = Expand[Together[(-(n + 4)*P[n - 1, x])/(-n)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten

P(N) = {my(v = vector(N + 1)); v[1] = 3; for(n = 1, N, my(i = n + 1); v[i] = (-(n + 4)*v[i - 1])/(-n)); 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)

Proved properties

• Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
  Every polynomial of the sequence has only real roots, inside the stated interval.
  by the cited steps: e-4347e41634c98e26
• Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
  All coefficients of each polynomial have the same sign (after x -> -x when alternating).
  derived from the cited steps by a stated theorem: e-4347e41634c98e26
• Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
  Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
  derived from the cited steps by a stated theorem: e-4347e41634c98e26

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

• gamma_polynomial scale 1, shift 0 e-4347e41634c98e26

  Gamma criterion RealRooted IsGammaExpansion.isRealRooted_and_hasRootsNonpos_iff ?

  • premise (sequence): Triangle read by rows, for 0 <= k <= n: T(n, k) = binomial(n, k) * binomial(binomial(n + 3, 2), 2).
    uses: Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    • theorem_check liu_wang e-e2cde2e22920ce64 root: theorem check

      Liu–Wang theorem [LW07, Thm 2.1, Cor 2.4] ?

    • preserver_image reversal, shift 0 e-4dae17a76888d380

      Affine, reversal and Möbius substitutions (elementary) polytool ?

      • premise (sequence): Triangle read by rows, for 0 <= k <= n: T(n, k) = binomial(n, k) * binomial(binomial(n + 3, 2), 2).
        uses: Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
        • ↵ theorem_check liu_wang e-e2cde2e22920ce64 (expanded above)

Related sequences ?

Same fingerprint (75)

Equal up to content, sign, reversal and a small index shift.

• A010054 → reverse → θ+1
• basis-map coefficients of Triangle read by rows: T(n,k) = binomial(k,n-k). shifted by x -> -x + 0
• basis-map coefficients of A030528, shifted → (θ+1)²
• basis-map coefficients of Square array of binomial coefficients T(n,k) = binomial(n,k), n >= 0, k >= 0, read by downwar…
• A136572 → θ+1
• A196347 → γ
• basis-map coefficients of A030528, shifted → reverse
• basis-map coefficients of A scaled Hermite triangle.
• A023531 → (θ+1)² → (θ+1)²
• A130123 → D
• A010054 → reverse → D
• A010054 → reverse → θ+1
• A136572 → D
• A178822 → γ
• A010054 → reverse → θ+1
• A136572: Triangle read by rows: row n consists of n zeros followed by n!.
• A038338 → γ
• A023531: a(n) = 1 if n is of the form m(m+3)/2, otherwise 0.
• A010054 → reverse → D
• basis-map coefficients of A021012 → D
• A130123 → (θ+1)²
• basis-map coefficients of A297191, shifted → θ+1
• A010054 → reverse → D
• A133080 → Veronese 2
• basis-map coefficients of A030528, shifted → D
• basis-map coefficients of A021012 → (θ+1)²
• basis-map coefficients of A112227 → θ+1
• A135838 → γ
• basis-map coefficients of A026729 → D
• A023531 → 2D+1+2n → Veronese 2 (j=1)
• basis-map coefficients of A112227 → (θ+1)²
• A127773: Triangle read by rows: row n consists of n-1 zeros followed by n(n+1)/2.
• A010054 → reverse → reverse
• basis-map coefficients of Irregular triangle read by rows formed by taking every other row of the Delannoy array (A0082…
• A130123 → θ+1
• A010054: a(n) = 1 if n is a triangular number, otherwise 0.
• A130123: Infinite lower triangular matrix with 2^k in the right diagonal and the rest zeros. Triangle, T(n,k), n zeros …
• A007318 → D → γ
• A178820 → γ
• A010054 → reverse → (θ+1)²
• A131431: 3n + 1 preceded by n zeros.
• A023531 → (θ+1)² → reverse
• A038325 → γ
• A127733: Triangle read by rows: n-th row is n^2 preceded by (n-1) zeros.
• basis-map coefficients of A026729, shifted → D
• basis-map coefficients of A026729, shifted → (θ+1)²
• basis-map coefficients of A026729, shifted → θ+1
• A136572 → (θ+1)²
• A356546 → γ
• A038221 → γ
• A132440: Infinitesimal Pascal matrix: generator (lower triangular matrix representation) of the Pascal matrix, the clas…
• A156992 → γ
• basis-map coefficients of A026729 → (θ+1)²
• A028326 → γ
• basis-map coefficients of Square array of binomial coefficients T(n,k) = binomial(n,k), n >= 0, k >= 0, read by downwar…
• A023531 → (θ+1)² → D
• basis-map coefficients of A297191, shifted → (θ+1)²
• basis-map coefficients of A026729, shifted → reverse
• A010054 → reverse → reverse
• A198954: Expansion of the rotational partition function for a heteronuclear diatomic molecule.
• basis-map coefficients of Triangle of coefficients in expansion of x^n in terms of Laguerre polynomials L_n(x).
• A023531 → D → (θ+1)²
• basis-map coefficients of A112227 → D
• basis-map coefficients of A030528, shifted → θ+1
• A127648: Triangle read by rows: row n consists of n zeros followed by n+1.
• A178821 → γ
• basis-map coefficients of A021012 → reverse
• A023531 → θ+1
• A085881 → γ
• A010054 → reverse → (θ+1)²
• basis-map coefficients of A021012 → θ+1
• A130123 → reverse
• basis-map coefficients of A297191, shifted → D
• A023531 → (θ+1)² → θ+1
• A023531 → 2D+1+2n → Veronese 2

References

1. [LW07] Lily L. Liu and Yi Wang. A unified approach to polynomial sequences with only real zeros. Advances in Applied Mathematics, 38(4):542–560, May 2007. doi:10.1016/j.aam.2006.02.003