A134346 → D

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(\left(2 - 3\,n + n^{2}\right)\,P_{n}(x) = \left(2\,n + 4\,n x + 2\,n x^{2} - 2\,n^{2} - 4\,n^{2} x - 2\,n^{2} x^{2}\right)\,P_{n-2}(x) + \left(-6\,n - 6\,n x + 3\,n^{2} + 3\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 3\)
\(P_{2}(x) = 14 + 14\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
133
2141428
3459045180
4124372372124992
53151260189012603155040
6762381076207620381076224384
7178510710267753570026775107101785114240
84088286168584814308014308085848286164088523264
99207736562577965155926444905155922577967365692072356992
102047018423073692017194802579220257922017194807369201842302047010480640
1145045450450202702554054009459450113513409459450540540020270254504504504546126080
1298292108121254060601621818032436360454109044541090432436360162181805406060108121298292201302016
132129792555748140566144685538010542460516867936819679259616867936810542460546855380140566142555748212979872361984
144587385963594357815641311990683279976705903958067871944087871944085903958063279976701311990683578156459635944587383757981696
Technical details
Node id
n-7a039e8d5dd81059 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-77a7ed3b1d5f257e

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:   14,    14;
  3:   45,    90,     45;
  4:  124,   372,    372,    124;
  5:  315,  1260,   1890,   1260,    315;
  6:  762,  3810,   7620,   7620,   3810,    762;
  7: 1785, 10710,  26775,  35700,  26775,  10710,   1785;
  8: 4088, 28616,  85848, 143080, 143080,  85848,  28616,  4088;
  9: 9207, 73656, 257796, 515592, 644490, 515592, 257796, 73656, 9207;
%F Formula
The row polynomials satisfy (n^2-3*n+2)*P(n,x) = -(2*n^2-2*n+(4*n^2-4*n)*x+(2*n^2-2*n)*x^2)*P(n-2,x) + (3*n^2-6*n+(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 + 14*x.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 3;
P[2, x_] := 14 + 14*x;
P[n_, x_] := P[n, x] = Expand[Together[(-(2*n^2 - 2*n + (4*n^2 - 4*n)*x + (2*n^2 - 2*n)*x^2)*P[n - 2, x] + (3*n^2 - 6*n + (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 + 14*x; for(n = 3, N, my(i = n + 1); v[i] = (-(2*n^2 - 2*n + (4*n^2 - 4*n)*x + (2*n^2 - 2*n)*x^2)*v[i - 2] + (3*n^2 - 6*n + (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.