A038338 → x ↦ x+1 → basis A013610

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(36 + 36\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1296 + 2592\,x + 1296\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
01296259212965184
14665613996813996846656373248
216796166718464100776966718464167961626873856
360466176302330880604661760604661760302330880604661761934917632
4217678233613060694016326517350404353564672032651735040130606940162176782336139314069504
57836416409654854914867216456474460162742745743360274274574336016456474460165485491486727836416409610030613004288
62821109907456225688792596487899107740876815798215481753619747769352192015798215481753678991077408768225688792596482821109907456722204136308736
71015599566684169140396100157443656158440062976853103636014694412796554540220416127965545402204168531036360146944365615844006297691403961001574410155995666841651998697814228992
Technical details
Node id
n-617ed248caa43f18 · revision 0 · JSON
Definition source
derived:basis_map_A013610
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

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:               1296,                2592,                1296;
  1:              46656,              139968,              139968,                46656;
  2:            1679616,             6718464,            10077696,              6718464,              1679616;
  3:           60466176,           302330880,           604661760,            604661760,            302330880,             60466176;
  4:         2176782336,         13060694016,         32651735040,          43535646720,          32651735040,          13060694016,           2176782336;
  5:        78364164096,        548549148672,       1645647446016,        2742745743360,        2742745743360,        1645647446016,         548549148672,          78364164096;
  6:      2821109907456,      22568879259648,      78991077408768,      157982154817536,      197477693521920,      157982154817536,       78991077408768,       22568879259648,        2821109907456;
  7:    101559956668416,     914039610015744,    3656158440062976,     8531036360146944,    12796554540220416,    12796554540220416,     8531036360146944,     3656158440062976,      914039610015744,     101559956668416;
  8:   3656158440062976,   36561584400629760,  164527129802833920,   438739012807557120,   767793272413224960,   921351926895869952,   767793272413224960,   438739012807557120,   164527129802833920,   36561584400629760,    3656158440062976;
  9: 131621703842267136, 1447838742264938496, 7239193711324692480, 21717581133974077440, 43435162267948154880, 60809227175127416832, 60809227175127416832, 43435162267948154880, 21717581133974077440, 7239193711324692480, 1447838742264938496, 131621703842267136;
%F Formula
The row polynomials satisfy P(n,x) = (36+36*x)*P(n-1,x) for n >= 1, with P(0,x) = 1296 + 2592*x + 1296*x^2.
%t Mathematica
P[0, x_] := 1296 + 2592*x + 1296*x^2;
P[n_, x_] := P[n, x] = Expand[(36 + 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] = 1296 + 2592*x + 1296*x^2; for(n = 1, N, my(i = n + 1); v[i] = (36 + 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)

polytool c48629374597

Properties

Proof chains ? JSON

Same fingerprint ?

References

  1. [Bra06] Petter Brändén. On linear transformations preserving the Pólya frequency property. Transactions of the American Mathematical Society, 358(8):3697–3716, February 2006. doi:10.1090/s0002-9947-06-03856-6
  2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  3. [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
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.