A038330 → basis A013611

palindromic γ-positive nonnegative coefficients only rational roots

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

Recurrence
\(P_{n}(x) = \left(16 + 16\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 256 + 512\,x + 256\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14x15x16Pn(1)
02565122561024
140961228812288409632768
265536262144393216262144655361048576
31048576524288010485760104857605242880104857633554432
416777216100663296251658240335544320251658240100663296167772161073741824
526843545618790481925637144576939524096093952409605637144576187904819226843545634359738368
64294967296343597383681202590842882405181685763006477107202405181685761202590842883435973836842949672961099511627776
7687194767366184752906242473901162496577243604582486586540687368658654068736577243604582424739011624966184752906246871947673635184372088832
810995116277761099511627776049478023249920131941395333120230897441832960277076930199552230897441832960131941395333120494780232499201099511627776010995116277761125899906842624
9175921860444161935140464885769675702324428802902710697328640580542139465728081275899525201928127589952520192580542139465728029027106973286409675702324428801935140464885761759218604441636028797018963968
1028147497671065633776997205278721857734846290329661924494876344320139330113471774720222928181554839552260082878480646144222928181554839552139330113471774720619244948763443201857734846290329633776997205278722814749767106561152921504606846976
114503599627370496585467951558164483512807709348986881288029493427961856322007373356990464057961327204258283527728176960567771136772817696056777113657961327204258283523220073733569904640128802949342796185635128077093489868858546795155816448450359962737049636893488147419103232
1272057594037927936100880631653099110465572410574514421762622896422980576870472129651631965863936144259303263931727872216388954895897591808247301662738168676352216388954895897591808144259303263931727872721296516319658639362622896422980576870465572410574514421761008806316530991104720575940379279361180591620717411303424
131152921504606846976172938225691027046401210567579837189324805245792845961153740801573737853788346122240346222327833436146892857703721305572691148807419049882145060290560741904988214506029056057703721305572691148803462223278334361468928157373785378834612224052457928459611537408012105675798371893248017293822569102704640115292150460684697637778931862957161709568
141844674407370955161629514790517935282585622136092888451461939201033017668127734890496033573074214151383941120805753781139633214586881477215265422660893409282110307522032372704870402374095962286419292979202110307522032372704870401477215265422660893409288057537811396332145868833573074214151383941120103301766812773489049602213609288845146193920295147905179352825856184467440737095516161208925819614629174706176

Computed in your browser ?

Technical details
Node id
n-b05662f2ce3af6a8 · revision 1 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-77a7ed3b1d5f257e

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: 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

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:            256,             512,             256;
  1:           4096,           12288,           12288,             4096;
  2:          65536,          262144,          393216,           262144,            65536;
  3:        1048576,         5242880,        10485760,         10485760,          5242880,          1048576;
  4:       16777216,       100663296,       251658240,        335544320,        251658240,        100663296,         16777216;
  5:      268435456,      1879048192,      5637144576,       9395240960,       9395240960,       5637144576,       1879048192,        268435456;
  6:     4294967296,     34359738368,    120259084288,     240518168576,     300647710720,     240518168576,     120259084288,      34359738368,       4294967296;
  7:    68719476736,    618475290624,   2473901162496,    5772436045824,    8658654068736,    8658654068736,    5772436045824,    2473901162496,     618475290624,     68719476736;
  8:  1099511627776,  10995116277760,  49478023249920,  131941395333120,  230897441832960,  277076930199552,  230897441832960,  131941395333120,   49478023249920,  10995116277760,   1099511627776;
  9: 17592186044416, 193514046488576, 967570232442880, 2902710697328640, 5805421394657280, 8127589952520192, 8127589952520192, 5805421394657280, 2902710697328640, 967570232442880, 193514046488576, 17592186044416;
%F Formula
The row polynomials satisfy P(n,x) = (16+16*x)*P(n-1,x) for n >= 1, with P(0,x) = 256 + 512*x + 256*x^2.
%t Mathematica
P[0, x_] := 256 + 512*x + 256*x^2;
P[n_, x_] := P[n, x] = Expand[(16 + 16*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] = 256 + 512*x + 256*x^2; for(n = 1, N, my(i = n + 1); v[i] = (16 + 16*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-dab838a9194ad2c3
  • 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-dab838a9194ad2c3
  • 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-dab838a9194ad2c3

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 (59)

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