A038338 → basis A013610

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, 0] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(P_{n}(x) = \left(24 + 36\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 576 + 1728\,x + 1296\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
0576172812963600
113824622089331246656216000
2331776199065644789764478976167961612960000
379626245971968017915904026873856020155392060466176777600000
41911029761719926784644972544012899450880145118822408707129344217678233646656000000
5458647142448157949952216710774784541776936960812665405440731398864896365699432448783641640962799360000000
61100753141761320903770112693474479308820804234379264390079394611204680952735334435107145515008150459195064322821109907456167961600000000
7264180754022435664401793024213986410758144748952437653504168514298472038425277144770805762527714477080576162495930669465660935974001049610155995666841610077696000000000

Computed in your browser ?

Technical details
Node id
n-67e5bcee85c7fcd9 · revision 1 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-f06e51c139cfae05

Observed on the stored rows ?

  • Degrees: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (affine: slope 1, intercept 2)
  • 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): yes

OEIS matches ?

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:              576,              1728,               1296;
  1:            13824,             62208,              93312,              46656;
  2:           331776,           1990656,            4478976,            4478976,             1679616;
  3:          7962624,          59719680,          179159040,          268738560,           201553920,            60466176;
  4:        191102976,        1719926784,         6449725440,        12899450880,         14511882240,          8707129344,          2176782336;
  5:       4586471424,       48157949952,       216710774784,       541776936960,        812665405440,        731398864896,        365699432448,         78364164096;
  6:     110075314176,     1320903770112,      6934744793088,     20804234379264,      39007939461120,      46809527353344,      35107145515008,      15045919506432,       2821109907456;
  7:    2641807540224,    35664401793024,    213986410758144,    748952437653504,    1685142984720384,    2527714477080576,    2527714477080576,    1624959306694656,     609359740010496,     101559956668416;
  8:   63403380965376,   951050714480640,   6419592322744320,  25678369290977280,   67405719388815360,  121330294899867648,  151662868624834560,  129996744535572480,   73123168801259520,   24374389600419840,   3656158440062976;
  9: 1521681143169024, 25107738862288896, 188308041467166720, 847386186602250240, 2542158559806750720, 5338532975594176512, 8007799463391264768, 8579785139347783680, 6434838854510837760, 3217419427255418880, 965225828176625664, 131621703842267136;
%F Formula
The row polynomials satisfy P(n,x) = (24+36*x)*P(n-1,x) for n >= 1, with P(0,x) = 576 + 1728*x + 1296*x^2.
%t Mathematica
P[0, x_] := 576 + 1728*x + 1296*x^2;
P[n_, x_] := P[n, x] = Expand[(24 + 36*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] = 576 + 1728*x + 1296*x^2; for(n = 1, N, my(i = n + 1); v[i] = (24 + 36*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)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-85e8843cd1dca083
  • Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
    All coefficients of each polynomial have the same sign (after x -> -x when alternating).
    derived from the cited steps by a stated theorem: e-85e8843cd1dca083
  • Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-85e8843cd1dca083

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

Same fingerprint (23)

Equal up to content, sign, reversal and a small index shift.

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