Real-rooted atlas

A063967 → basis A013611 → basis A013609

nonnegative coefficients

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
26814
34210464210
4288105612805123136
5198096001734413824409646844
6136088208019699223500813926432768699720
793528674784201945632076802850816134348826214410451896
8642816539827219353600383877124548198432178176125829122097152156122624
9441806442329088176822784420556800622759936587792384345243648115343360167772162332043280
1030365280326851200155887718443230781447681007616906575872071067238403567255552104018739213421772834834322656
112087000642493348480133676421124234740940887771684864124351447040121940213760817113333763580257894492610232321073741824520329123104
121434392064188337208321121207132163994350796809460800552961564124774400184161927168015440470343689032853094403511135764488160437862485899345927772288240640
13985855276814110715289692354668646436546017771529737370353664184016712499202528916668416025463026089984186405942722569674950705152337906552012871296457113668719476736116096643092416
14677576689921049988801024749353138790432609560338432965329973084162052623794176003225110839296003790887263928323333198624849922165074223431681009725336453123201468622438461847529062405497558138881734165038662784
15465697330560776750549760060031236077568284921597288448927735502897152219214724530176038761139090227205209712519806976534817676040601641727778923479042435568579379200103117869809664029934204066201653326313947136439804651110425903663544572800
Technical details
Node id
n-56628a2ba2240a48 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-69a27ac83c6caaaa

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,         8;
   3:       42,       104,         64;
   4:      288,      1056,       1280,        512;
   5:     1980,      9600,      17344,      13824,       4096;
   6:    13608,     82080,     196992,     235008,     139264,      32768;
   7:    93528,    674784,    2019456,    3207680,    2850816,    1343488,     262144;
   8:   642816,   5398272,   19353600,   38387712,   45481984,   32178176,   12582912,    2097152;
   9:  4418064,  42329088,  176822784,  420556800,  622759936,  587792384,  345243648,  115343360,   16777216;
  10: 30365280, 326851200, 1558877184, 4323078144, 7681007616, 9065758720, 7106723840, 3567255552, 1040187392, 134217728;
%F Formula
The row polynomials satisfy P(n,x) = (6+8*x)*P(n-2,x) + (6+8*x)*P(n-1,x) for n >= 3, with P(1,x) = 1, P(2,x) = 6 + 8*x.
%t Mathematica
P[1, x_] := 1;
P[2, x_] := 6 + 8*x;
P[n_, x_] := P[n, x] = Expand[(6 + 8*x)*P[n - 2, x] + (6 + 8*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 + 8*x; for(n = 3, N, my(i = n); v[i] = (6 + 8*x)*v[i - 2] + (6 + 8*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

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. [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