A099097 → basis A007318 → basis A013611

nonnegative coefficients

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
261218
338148144330
42401392268817286048
5151611680337124320020736110844
69576920163533766779526497282488322031480
76048869643233385928529472122480649372672298598437231704
83820805126784294635529400934417985331220630937613138329635831808682359552
Technical details
Node id
n-27830fbb0f09c824 · revision 0 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-6fbed9d7a4fd25c7

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 -1)
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:        1;
   2:        6,        12;
   3:       38,       148,        144;
   4:      240,      1392,       2688,       1728;
   5:     1516,     11680,      33712,      43200,       20736;
   6:     9576,     92016,     353376,     677952,      649728,      248832;
   7:    60488,    696432,    3338592,    8529472,    12248064,     9372672,     2985984;
   8:   382080,   5126784,   29463552,   94009344,   179853312,   206309376,   131383296,    35831808;
   9:  2413456,  36980480,  247765632,  948032000,  2265846016,  3463833600,  3307474944,  1803534336,   429981696;
  10: 15244896, 262626240, 2009793792, 8967252480, 25707204096, 49105185792, 62498856960, 51108102144, 24365629440, 5159780352;
%F Formula
The row polynomials satisfy P(n,x) = (2+4*x)*P(n-2,x) + (6+12*x)*P(n-1,x) for n >= 3, with P(1,x) = 1, P(2,x) = 6 + 12*x.
%t Mathematica
P[1, x_] := 1;
P[2, x_] := 6 + 12*x;
P[n_, x_] := P[n, x] = Expand[(2 + 4*x)*P[n - 2, x] + (6 + 12*x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; v[2] = 6 + 12*x; for(n = 3, N, my(i = n); v[i] = (2 + 4*x)*v[i - 2] + (6 + 12*x)*v[i - 1]); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

polytool c48629374597

Properties

Proof chains ? JSON

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. [MW08] Shi-Mei Ma and Yi Wang. q-Eulerian polynomials and polynomials with only real zeros. The Electronic Journal of Combinatorics, 15(1):Research Paper 17, January 2008. doi:10.37236/741