A038284 → D

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No OEIS matches.

Submission text ?

Triangle begins:
  0:          96,           72;
  1:        1152,         1728,           648;
  2:       12288,        27648,         20736,          5184;
  3:      122880,       368640,        414720,        207360,         38880;
  4:     1179648,      4423680,       6635520,       4976640,       1866240,        279936;
  5:    11010048,     49545216,      92897280,      92897280,      52254720,      15676416,       1959552;
  6:   100663296,    528482304,    1189085184,    1486356480,    1114767360,     501645312,     125411328,      13436928;
  7:   905969664,   5435817984,   14269022208,   21403533312,   20065812480,   12039487488,    4514807808,     967458816,     90699264;
  8:  8053063680,  54358179840,  163074539520,  285380444160,  321052999680,  240789749760,  120394874880,   38698352640,   7255941120,   604661760;
  9: 70866960384, 531502202880, 1793819934720, 3587639869440, 4708777328640, 4237899595776, 2648687247360, 1135151677440, 319261409280, 53210234880, 3990767616;

The row polynomials satisfy (n+1)*P(n,x) = (8*n+16+(6*n+12)*x)*P(n-1,x) for n >= 1, with P(0,x) = 96 + 72*x.

P[0, x_] := 96 + 72*x;
P[n_, x_] := P[n, x] = Expand[Together[((8*n + 16 + (6*n + 12)*x)*P[n - 1, x])/(n + 1)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten

P(N) = {my(v = vector(N + 1)); v[1] = 96 + 72*x; for(n = 1, N, my(i = n + 1); v[i] = ((8*n + 16 + (6*n + 12)*x)*v[i - 1])/(n + 1)); 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
• Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 1
  by Laguerre’s theorem on differential operators

Proof chains ? JSON

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

  • from Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*6^j.?
    • 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
    • Liu–Wang theorem [LW07, Thm 2.1, Cor 2.4] ? step › direct check
    • Parent-row provers of polytool polytool ? step › direct check
    • Iterated real-rootedness preservers [SP14; Bra15, Thm 7.1 of arXiv:1410.6601; Bra06, Cor 3.5] polytool ? step › direct check

Related ?

Same fingerprint ?

• A013609 → basis A013609 → D
• A038279 → basis A013610 → x ↦ x/(x+1)
• A120909 → basis A013610 → basis A013609
• A013610 → basis A007318 → D
• A120910 → D → basis A013611
• A027465 → D → basis A013610
• A196347 → basis A013611 → basis A013609
• basis-map coefficients of A026729 → basis A013609 → basis A013609
• basis-map coefficients of A026729 → basis A013610 → basis A007318
• A120910 → basis A013611 → reverse
• A038330 → basis A013610 → D
• A038329 → basis A013611 → basis A013610
• A038335 → D
• A038208 → basis A013611 → basis A013609
• A094305 → x ↦ x+1 → basis A013611
• A196347 → x ↦ x+1 → basis A013611
• A085880 → x ↦ x+1 → basis A013611
• basis-map coefficients of A030528, shifted → basis A013610 → x ↦ x+1
• A178821 → basis A013611 → basis A013609
• A013610 → basis A007318
• A085880 → basis A013611 → basis A013609
• A120910 → basis A013611 → D
• A013610 → basis A013611 → x ↦ x+1
• A178820 → basis A013611 → basis A013609
• A038284 → reverse
• basis-map coefficients of A112227 → basis A013609 → basis A013609
• A135065 → x ↦ x+1 → basis A013611
• A038330 → basis A013610
• basis-map coefficients of A030528, shifted → basis A013609 → basis A013609
• basis-map coefficients of A112227 → basis A013610 → basis A007318
• A130123 → basis A013610 → x ↦ x+1
• A038335 → reverse
• A120910 → basis A013611
• A003506 → x ↦ x+1 → basis A013611
• A085881 → basis A013611 → basis A013609
• Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*6^j.
• A038330 → basis A013610 → reverse
• A156992 → basis A013611 → basis A013609
• basis-map coefficients of A026729, shifted → basis A013609 → basis A013609
• A130123 → basis A013609 → basis A013609
• A013609 → basis A013609
• A178822 → x ↦ x+1 → basis A013611
• A028326 → basis A007318 → basis A013611
• A356546 → x ↦ x+1 → basis A013611
• A178822 → basis A013611 → basis A013609
• A038221 → basis A013611 → basis A013609
• A178820 → basis A007318 → basis A013611
• A013609 → D → basis A013609
• A178821 → basis A007318 → basis A013611
• A038329 → basis A013610 → basis A013609
• A356546 → basis A013611 → basis A013609
• A136572 → basis A013610 → basis A007318
• A038335: Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*9^j.
• A028326 → basis A013611 → basis A013609
• A038334 → basis A013609 → basis A013610
• A038243 → basis A013609 → x ↦ x/(x+1)
• A038330 → x ↦ x/(x+1)
• basis-map coefficients of A026729, shifted → basis A013610 → x ↦ x+1
• A027465 → x ↦ x/(x+1)

References

1. [Bra06] Petter Brändén. On linear transformations preserving the Pólya frequency property. Transactions of the American Mathematical Society, 358(8):3697–3716, February 2006. doi:10.1090/s0002-9947-06-03856-6
2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
3. [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
4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.