A038338 → basis A007318

nonnegative coefficients only rational roots

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

Recurrence
\(P_{n}(x) = \left(24 + 12\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 576 + 576\,x + 144\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
05765761441296
1138242073610368172846656
2331776663552497664165888207361679616
3796262419906560199065609953280248832024883260466176
41911029765733089287166361604777574401791590403583180829859842176782336
545864714241605264998424078974976200658124801003290624030098718725016453123583180878364164096
61100753141764403012567047705271992327705271992324815794995201926317998084815794995268797071364299816962821109907456
7264180754022411888133931008237762678620162773897917235220804234379264104021171896323467372396544743008370688928760463365159780352101559956668416

Computed in your browser ?

Technical details
Node id
n-2db2a1c44af41062 · revision 1 · JSON
Definition source
derived:basis_map_A007318
Fingerprint
f6-11aec07ce60b6d61

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,              576,               144;
  1:            13824,            20736,             10368,              1728;
  2:           331776,           663552,            497664,            165888,             20736;
  3:          7962624,         19906560,          19906560,           9953280,           2488320,            248832;
  4:        191102976,        573308928,         716636160,         477757440,         179159040,          35831808,           2985984;
  5:       4586471424,      16052649984,       24078974976,       20065812480,       10032906240,        3009871872,         501645312,         35831808;
  6:     110075314176,     440301256704,      770527199232,      770527199232,      481579499520,      192631799808,       48157949952,       6879707136,       429981696;
  7:    2641807540224,   11888133931008,    23776267862016,    27738979172352,    20804234379264,    10402117189632,     3467372396544,     743008370688,     92876046336,      5159780352;
  8:   63403380965376,  317016904826880,   713288035860480,   951050714480640,   832169375170560,   499301625102336,   208042343792640,   59440669655040,  11145125560320,   1238347284480,    61917364224;
  9: 1521681143169024, 8369246287429632, 20923115718574080, 31384673577861120, 31384673577861120, 21969271504502784, 10984635752251392, 3923084197232640, 980771049308160, 163461841551360, 16346184155136, 743008370688;
%F Formula
The row polynomials satisfy P(n,x) = (24+12*x)*P(n-1,x) for n >= 1, with P(0,x) = 576 + 576*x + 144*x^2.
%t Mathematica
P[0, x_] := 576 + 576*x + 144*x^2;
P[n_, x_] := P[n, x] = Expand[(24 + 12*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 + 576*x + 144*x^2; for(n = 1, N, my(i = n + 1); v[i] = (24 + 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 - 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-a2ff444bbbdc7b83
  • 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-a2ff444bbbdc7b83
  • 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-a2ff444bbbdc7b83

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 (67)

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