A028326 → basis A013611 → basis A013611

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Submission text ?

Triangle begins:
  0:        2;
  1:       12,        32;
  2:       72,       384,        512;
  3:      432,      3456,       9216,        8192;
  4:     2592,     27648,     110592,      196608,       131072;
  5:    15552,    207360,    1105920,     2949120,      3932160,      2097152;
  6:    93312,   1492992,    9953280,    35389440,     70778880,     75497472,     33554432;
  7:   559872,  10450944,   83607552,   371589120,    990904320,   1585446912,   1409286144,    536870912;
  8:  3359232,  71663616,  668860416,  3567255552,  11890851840,  25367150592,  33822867456,  25769803776,   8589934592;
  9: 20155392, 483729408, 5159780352, 32105299968, 128421199872, 342456532992, 608811614208, 695784701952, 463856467968, 137438953472;

The row polynomials satisfy P(n,x) = (6+16*x)*P(n-1,x) for n >= 1, with P(0,x) = 2.

P[0, x_] := 2;
P[n_, x_] := P[n, x] = Expand[(6 + 16*x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten

P(N) = {my(v = vector(N + 1)); v[1] = 2; for(n = 1, N, my(i = n + 1); v[i] = (6 + 16*x)*v[i - 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 Geometric basis map (elementary)
• Coefficients of one sign? Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
  derived from Geometric basis map (elementary)
• Hadamard kernel (Malo)? Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
  derived from Geometric basis map (elementary)

Proof chains ? JSON

• Geometric basis map (elementary) polytool ? step ›

  • from basis_map_A013611 of Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).?
    • Geometric basis map (elementary) polytool ? step ›

      • from Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).?
        • Liu–Wang theorem [LW07, Thm 2.1, Cor 2.4] ? step › direct check
        • 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 Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).?
            • ↑ Liu–Wang theorem (above)
            • ↑ Row-hypergeometric rows (multiplier sequences) (above)
            • 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
        • ↑ Parent-row provers of polytool (above)
        • ↑ Iterated real-rootedness preservers (above)
    • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

      • from basis_map_A013609 of Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).?
        • Geometric basis map (elementary) polytool ? step ›

          • from Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).?
            • ↑ Liu–Wang theorem (above)
            • ↑ Row-hypergeometric rows (multiplier sequences) (above)
            • ↑ Affine, reversal and Möbius substitutions (elementary) (above)
            • ↑ Parent-row provers of polytool (above)
            • ↑ Iterated real-rootedness preservers (above)
        • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

          • from basis_map_A013609 of Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).?
            • ↑ Geometric basis map (elementary) (above)

Related ?

Same fingerprint ?

• A038281 → D
• A013622 → x ↦ x/(x+1) → D
• Triangle read by rows: (i,j)-th entry is binomial(i,j)*3^(i-j)*8^j.
• A038208 → basis A013611 → basis A013611
• A038281: Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*3^j.
• basis-map coefficients of A030528, shifted → basis A013609 → basis A013611
• A013622 → x ↦ x/(x+1)
• A013612 → basis A013609 → x ↦ x/(x+1)
• basis-map coefficients of A026729 → basis A013609 → basis A013611
• A120909 → basis A013611
• A130123 → basis A013609 → basis A013611
• A038329 → basis A013610 → basis A007318
• A013609 → D → basis A013611
• A038327 → basis A013610 → basis A013609
• A178821 → basis A013611 → basis A013611
• A013609 → basis A013610 → basis A013611
• A136572 → basis A013609 → basis A013611
• A027466 → basis A013610 → D
• A178820 → basis A013611 → basis A013611
• A038226 → D
• basis-map coefficients of A112227 → basis A013609 → basis A013611
• A038271 → basis A013611 → x ↦ x/(x+1)
• A120909 → basis A013610 → basis A013611
• basis-map coefficients of A026729, shifted → basis A013609 → basis A013611
• A038328 → x ↦ x+1 → basis A013610
• A027466 → basis A013610

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.