A132774 → Veronese 2 (j=1) → (θ+1)²

palindromicγ-positivenonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(16\right)\,P_{n}(x) = \left(-872\,x^{3} + 873\,n x^{3} - 261\,n^{2} x^{3} + 18\,n^{3} x^{3}\right)\,P_{n-6}(x) + \left(-258\,x^{4} + 234\,n x^{4} - 54\,n^{2} x^{4}\right)\,P_{n-6}'(x) + \left(2556\,x^{2} - 2070\,n x^{2} + 486\,n^{2} x^{2} - 36\,n^{3} x^{2}\right)\,P_{n-4}(x) + \left(1092\,x^{3} - 756\,n x^{3} + 108\,n^{2} x^{3}\right)\,P_{n-4}'(x) + \left(-1092\,x + 909\,n x - 225\,n^{2} x + 18\,n^{3} x\right)\,P_{n-2}(x) + \left(-1266\,x^{2} + 522\,n x^{2} - 54\,n^{2} x^{2}\right)\,P_{n-2}'(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 3\)
\(P_{2}(x) = 4\)
\(P_{3}(x) = 28\,x\)
\(P_{4}(x) = 32\,x\)
\(P_{5}(x) = 99\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6Pn(1)
00
133
244
302828
403232
5009999
600108108
7000240240
8000256256
90000475475
100000500500
1100000828828
1200000864864
1300000013231323
1400000013721372
Technical details
Node id
n-3f0002a715c9c816 · revision 0 · JSON
Definition source
derived:theta_plus_one_squared
Fingerprint
f6-edf6954a4cd8adfc

Observed on the stored rows ?

  • Degrees: -1, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6 (half affine: slope 1, intercept -1)
  • Palindromic rows: yes
  • γ-positive (gamma_positive): yes
  • Nonnegative coefficients (nonn): yes
  • Only rational roots (rr_by_factors: every nonzero row is a product of linear factors over ℚ): yes

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0: 0;
  1: 3;
  2: 4;
  3: 0, 28;
  4: 0, 32;
  5: 0,  0,  99;
  6: 0,  0, 108;
  7: 0,  0,   0, 240;
  8: 0,  0,   0, 256;
  9: 0,  0,   0,   0, 475;
%F Formula
The row polynomials satisfy 16*P(n,x) = (18*n^3-261*n^2+873*n-872)*x^3*P(n-6,x) - (54*n^2-234*n+258)*x^4*d/dx P(n-6,x) - (36*n^3-486*n^2+2070*n-2556)*x^2*P(n-4,x) + (108*n^2-756*n+1092)*x^3*d/dx P(n-4,x) + (18*n^3-225*n^2+909*n-1092)*x*P(n-2,x) - (54*n^2-522*n+1266)*x^2*d/dx P(n-2,x) for n >= 6, with P(0,x) = 0, P(1,x) = 3, P(2,x) = 4, P(3,x) = 28*x, P(4,x) = 32*x, P(5,x) = 99*x^2.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 3;
P[2, x_] := 4;
P[3, x_] := 28*x;
P[4, x_] := 32*x;
P[5, x_] := 99*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((18*n^3 - 261*n^2 + 873*n - 872)*x^3*P[n - 6, x] - (54*n^2 - 234*n + 258)*x^4*D[P[n - 6, x], x] - (36*n^3 - 486*n^2 + 2070*n - 2556)*x^2*P[n - 4, x] + (108*n^2 - 756*n + 1092)*x^3*D[P[n - 4, x], x] + (18*n^3 - 225*n^2 + 909*n - 1092)*x*P[n - 2, x] - (54*n^2 - 522*n + 1266)*x^2*D[P[n - 2, x], x])/(16)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = 3; v[3] = 4; v[4] = 28*x; v[5] = 32*x; v[6] = 99*x^2; for(n = 6, N, my(i = n + 1); v[i] = ((18*n^3 - 261*n^2 + 873*n - 872)*x^3*v[i - 6] - (54*n^2 - 234*n + 258)*x^4*deriv(v[i - 6], x) - (36*n^3 - 486*n^2 + 2070*n - 2556)*x^2*v[i - 4] + (108*n^2 - 756*n + 1092)*x^3*deriv(v[i - 4], x) + (18*n^3 - 225*n^2 + 909*n - 1092)*x*v[i - 2] - (54*n^2 - 522*n + 1266)*x^2*deriv(v[i - 2], x))/(16)); 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)

polytool c48629374597

Properties

Proof chains ? JSON

Same fingerprint ?

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.