Real-rooted atlas

A232535 → basis A007318 → reverse

nonnegative coefficients

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

Recurrence

\(\left(n^{2}\right)\,P_{n}(x) = \left(-3\,x - 6\,x^{2} + n + 4\,n x + 12\,n x^{2} + n^{2} + 2\,n^{2} x - 6\,n^{2} x^{2}\right)\,P_{n-1}(x) + \left(3\,x^{2} + 6\,x^{3} + 2\,n x + 2\,n x^{2}\right)\,P_{n-1}'(x) + \left(6\,x^{3} + 6\,x^{4}\right)\,P_{n-1}''(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
1235
23141229
34378048169
4576296416192985
56135816196820487685741
6721818766784117769728307233461
7832938081910448640657924505612288195025

All 15 rows

Technical details
Node id
n-171bd91c8b97fcd1 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-2ab9eb92c097ff31

Observed on the stored rows ?

  • Degrees: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 (affine: slope 1, intercept 0)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • Nonnegative coefficients (nonn): yes
  • Only rational roots (rr_by_factors: every nonzero row is a product of linear factors over ℚ): no

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:  1;
  1:  2,   3;
  2:  3,  14,    12;
  3:  4,  37,    80,     48;
  4:  5,  76,   296,    416,    192;
  5:  6, 135,   816,   1968,   2048,     768;
  6:  7, 218,  1876,   6784,  11776,    9728,    3072;
  7:  8, 329,  3808,  19104,  48640,   65792,   45056,   12288;
  8:  9, 472,  7056,  46656, 161920,  316416,  350208,  204800,  49152;
  9: 10, 651, 12192, 102432, 461824, 1214720, 1921024, 1798144, 917504, 196608;
%F Formula
The row polynomials satisfy n^2*P(n,x) = (n^2+n+(2*n^2+4*n-3)*x-(6*n^2-12*n+6)*x^2)*P(n-1,x) + (2*n*x+(2*n+3)*x^2+6*x^3)*d/dx P(n-1,x) + (6*x^3+6*x^4)*d^2/dx^2 P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n^2 + n + (2*n^2 + 4*n - 3)*x - (6*n^2 - 12*n + 6)*x^2)*P[n - 1, x] + (2*n*x + (2*n + 3)*x^2 + 6*x^3)*D[P[n - 1, x], x] + (6*x^3 + 6*x^4)*D[P[n - 1, x], {x, 2}])/(n^2)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = ((n^2 + n + (2*n^2 + 4*n - 3)*x - (6*n^2 - 12*n + 6)*x^2)*v[i - 1] + (2*n*x + (2*n + 3)*x^2 + 6*x^3)*deriv(v[i - 1], x) + (6*x^3 + 6*x^4)*deriv(deriv(v[i - 1], x), x))/(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

Candidate equalities ?

Same fingerprint ?

References

  1. [Fav35] Jean Favard. Sur les polynômes de tchebicheff. C. R. Acad. Sci. Paris, 200:2052–2053, 1935.
  2. [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
  3. [Sze39] G. Szegő. Orthogonal Polynomials. Colloquium publications, American Mathematical Society, 1939. doi:10.1090/coll/023