image under θ+1 → basis A013611

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Triangle begins:
  0:  1;
  1:  2,   8;
  2:  3,  24,   48;
  3:  4,  48,  192,   256;
  4:  5,  80,  480,  1280,   1280;
  5:  6, 120,  960,  3840,   7680,    6144;
  6:  7, 168, 1680,  8960,  26880,   43008,   28672;
  7:  8, 224, 2688, 17920,  71680,  172032,  229376,  131072;
  8:  9, 288, 4032, 32256, 161280,  516096, 1032192, 1179648,  589824;
  9: 10, 360, 5760, 53760, 322560, 1290240, 3440640, 5898240, 5898240, 2621440;

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

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

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

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)
• Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 1
  by Geometric basis map (elementary)
• Real-rooted? Every row P_n, n ≥ 1, is zero or real-rooted with all roots in (−∞, 0]
  by Geometric basis map (elementary)
• Coefficients of one sign? Every nonzero row, n ≥ 1: the coefficients of P_n have one sign
  derived from Geometric basis map (elementary)
• Hadamard kernel (Malo)? Rows P_n, n ≥ 1, are Hadamard kernels (preserve real-rootedness)
  derived from Geometric basis map (elementary)
• Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 2
  by Geometric basis map (elementary)

Proof chains ? JSON

• Geometric basis map (elementary) polytool ? step ›

  • from derivative of basis-map coefficients of A scaled Hermite triangle.?
    • Laguerre’s theorem on differential operators [SP14] polytool ? step ›

      • from basis-map coefficients of A scaled Hermite triangle.?
        • 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
        • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

          • from basis-map coefficients of A scaled Hermite triangle.?
            • ↑ Parent-row provers of polytool (above)
            • ↑ Iterated real-rootedness preservers (above)
• Geometric basis map (elementary) polytool ? step ›

  • from theta_plus_one of a(n) = 1 if n is of the form m(m+3)/2, otherwise 0.?
    • Liu–Wang theorem for three-term recurrences [LW07, Thm 2.1, Thm 2.3, Cor 2.4, Prop 3.3] polytool ? step › direct check
    • Laguerre’s theorem on multiplier sequences [SP14; Bra15, Thm 7.1 of arXiv:1410.6601] polytool ? step ›

      • from a(n) = 1 if n is of the form m(m+3)/2, otherwise 0.?
        • Iterated real-rootedness preservers [SP14; Bra15, Thm 7.1 of arXiv:1410.6601; Bra06, Cor 3.5] polytool ? step › direct check
        • Veronese sections of Pólya frequency sequences [ASW52; Edr53; AW24] polytool ? step ›

          • from basis-map coefficients of Irregular triangle read by rows formed by taking every other row of the Delannoy array (A0082…?
            • 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
            • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

              • from basis-map coefficients of Irregular triangle read by rows formed by taking every other row of the Delannoy array (A0082…?
                • ↑ Parent-row provers of polytool (above)
                • ↑ Iterated real-rootedness preservers (above)
        • Parent-row provers of polytool polytool ? step › direct check
        • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

          • from a(n) = 1 if n is of the form m(m+3)/2, otherwise 0.?
            • ↑ Iterated real-rootedness preservers (above)
            • ↑ Veronese sections of Pólya frequency sequences (above)
            • ↑ Parent-row provers of polytool (above)
    • Affine, reversal and Möbius substitutions (elementary) polytool ? step ›

      • from theta_plus_one of a(n) = 1 if n is of the form m(m+3)/2, otherwise 0.?
        • ↑ Liu–Wang theorem for three-term recurrences (above)
        • ↑ Laguerre’s theorem on multiplier sequences (above)

Related ?

Same fingerprint ?

• basis-map coefficients of A112227 → basis A013611 → D
• Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*3^j.
• basis-map coefficients of A112227 → basis A013611
• basis-map coefficients of A112227 → θ+1 → basis A013611
• A038231 → D → D
• basis-map coefficients of A030528, shifted → θ+1 → basis A013611
• A038330 → basis A007318 → D
• A136572 → D → basis A013611
• A013611 → D
• basis-map coefficients of A026729 → (θ+1)² → basis A013611
• basis-map coefficients of A030528, shifted → D → basis A013611
• A136572 → basis A013611 → D
• A134309 → basis A013611
• A130123 → D → basis A013611
• A027466 → basis A013609 → D
• basis-map coefficients of A112227 → (θ+1)² → basis A013611
• A013610 → basis A013611 → x ↦ x/(x+1)
• basis-map coefficients of A112227 → basis A013611 → reverse
• A130123 → basis A013611 → D
• A129186 → basis A013611
• basis-map coefficients of A026729 → D → basis A013611
• A013611: Triangle of coefficients in expansion of (1+4x)^n.
• A131431 → D → basis A013611
• A027467 → basis A013611 → reverse
• image under θ+1 → (θ+1)² → basis A013611
• A136572 → basis A013611 → reverse
• A027467 → basis A013611
• basis-map coefficients of A026729, shifted → basis A013611
• A027467 → basis A013611 → D
• A027466 → basis A013609
• A038231 → D
• A132440 → basis A013611
• A136572 → θ+1 → basis A013611
• A127648 → D → basis A013611
• A131436 → basis A013611
• A038330 → basis A007318
• A130123 → (θ+1)² → basis A013611
• A013611 → D → D
• basis-map coefficients of A026729, shifted → θ+1 → basis A013611
• A120910 → basis A007318 → basis A007318
• basis-map coefficients of A026729 → basis A013611 → reverse
• A038303 → basis A007318 → basis A013610
• basis-map coefficients of A026729 → basis A013611 → D
• A136521 → basis A013611
• basis-map coefficients of A026729, shifted → (θ+1)² → basis A013611
• A038231: Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j).
• A130123 → basis A013611
• basis-map coefficients of A026729 → basis A013611
• basis-map coefficients of A030528, shifted → (θ+1)² → basis A013611
• A038330 → basis A007318 → reverse
• basis-map coefficients of A026729, shifted → D → basis A013611
• basis-map coefficients of A021012 → θ+1 → basis A013611
• A130123 → θ+1 → basis A013611
• A136572 → (θ+1)² → basis A013611
• A131431 → basis A013611
• A136572 → basis A013611
• A132440 → θ+1 → basis A013611
• image under θ+1 → θ+1 → D → basis A013611
• A038329 → reverse
• basis-map coefficients of A030528, shifted → basis A013611
• A038329 → D
• A131431 → θ+1 → basis A013611
• basis-map coefficients of A021012 → basis A013611

References

1. [ASW52] Michael Aissen, I. J. Schoenberg and A. M. Whitney. On the generating functions of totally positive sequences I. Journal d’Analyse Mathématique, 2(1):93–103, 1952. doi:10.1007/BF02786970
2. [AW24] Christos A. Athanasiadis and David G. Wagner. Veronese sections and interlacing matrices of polynomials and formal power series. arXiv:2404.12989. arXiv
3. [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
4. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
5. [Edr53] Albert Edrei. Proof of a Conjecture of Schoenberg on the Generating Function of a Totally Positive Sequence. Canadian Journal of Mathematics, 5:86–94, 1953. doi:10.4153/CJM-1953-010-3
6. [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
7. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.