A134346 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(-8 - 16\,x - 8\,x^{2}\right)\,P_{n-2}(x) + \left(6 + 6\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)
\(P_{1}(x) = 6 + 6\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
16612
2285628112
3120360360120960
44961984297619844967936
5201610080201602016010080201664512
6812848768121920162560121920487688128520192
73264022848068544011424001142400685440228480326404177920
8130816104652836628487325696915712073256963662848104652813081633488896
952377647139841885593643997184659957766599577643997184188559364713984523776268173312
1020961282096128094325760251535360440186880528224256440186880251535360943257602096128020961282146435072
1183865609225216046126080013837824002767564800387459072038745907202767564800138378240046126080092252160838656017175674880
12335503364026040322214322176738107392016607416320265718661123100051046426571866112166074163207381073920221432217640260403233550336137422176256
13134209536174472396810468343808383839272969595981824017272767283223030356377623030356377617272767283295959818240383839272961046834380817447239681342095361099444518912
14536854528751596339248853762048195415048192537391382528107478276505616121741475841842484740096161217414758410747827650565373913825281954150481924885376204875159633925368545288795824586752
Technical details
Node id
n-93c333497b9fec47 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-77a7ed3b1d5f257e

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: 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:      1;
  1:      6,       6;
  2:     28,      56,       28;
  3:    120,     360,      360,      120;
  4:    496,    1984,     2976,     1984,      496;
  5:   2016,   10080,    20160,    20160,    10080,     2016;
  6:   8128,   48768,   121920,   162560,   121920,    48768,     8128;
  7:  32640,  228480,   685440,  1142400,  1142400,   685440,   228480,    32640;
  8: 130816, 1046528,  3662848,  7325696,  9157120,  7325696,  3662848,  1046528,  130816;
  9: 523776, 4713984, 18855936, 43997184, 65995776, 65995776, 43997184, 18855936, 4713984, 523776;
%F Formula
The row polynomials satisfy P(n,x) = -(8+16*x+8*x^2)*P(n-2,x) + (6+6*x)*P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 6 + 6*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 6 + 6*x;
P[n_, x_] := P[n, x] = Expand[-(8 + 16*x + 8*x^2)*P[n - 2, x] + (6 + 6*x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; v[2] = 6 + 6*x; for(n = 2, N, my(i = n + 1); v[i] = -(8 + 16*x + 8*x^2)*v[i - 2] + (6 + 6*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 - 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