A131436 → D

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(\left(2 - 3\,n + n^{2}\right)\,P_{n}(x) = \left(2\,n x^{2} - 2\,n^{2} x^{2}\right)\,P_{n-2}(x) + \left(-6\,n x + 3\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 3\)
\(P_{2}(x) = 14\,x\)

Rows ?

nx0x1x2x3x4x5x6Pn(1)
00
133
201414
3004545
4000124124
50000315315
600000762762
700000017851785
Technical details
Node id
n-4bc6a943f8bb5fc8 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-edf6954a4cd8adfc

Observed on the stored rows ?

  • Degrees: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (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: 0, 14;
  3: 0,  0, 45;
  4: 0,  0,  0, 124;
  5: 0,  0,  0,   0, 315;
  6: 0,  0,  0,   0,   0, 762;
  7: 0,  0,  0,   0,   0,   0, 1785;
  8: 0,  0,  0,   0,   0,   0,    0, 4088;
  9: 0,  0,  0,   0,   0,   0,    0,    0, 9207;
%F Formula
The row polynomials satisfy (n^2-3*n+2)*P(n,x) = -(2*n^2-2*n)*x^2*P(n-2,x) + (3*n^2-6*n)*x*P(n-1,x) for n >= 3, with P(0,x) = 0, P(1,x) = 3, P(2,x) = 14*x.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 3;
P[2, x_] := 14*x;
P[n_, x_] := P[n, x] = Expand[Together[(-(2*n^2 - 2*n)*x^2*P[n - 2, x] + (3*n^2 - 6*n)*x*P[n - 1, x])/(n^2 - 3*n + 2)]];
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] = 14*x; for(n = 3, N, my(i = n + 1); v[i] = (-(2*n^2 - 2*n)*x^2*v[i - 2] + (3*n^2 - 6*n)*x*v[i - 1])/(n^2 - 3*n + 2)); 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. [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
  2. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.