A120910 → basis A013610 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(6 + 6\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 3\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
033
1181836
2108216108432
3648194419446485184
43888155522332815552388862208
52332811664023328023328011664023328746496
61399688398082099520279936020995208398081399688957952
78398085878656176359682939328029393280176359685878656839808107495424
85038848403107841410877442821754883527193602821754881410877444031078450388481289945088
9302330882720977921088391168253957939238093690883809369088253957939210883911682720977923023308815479341056
1018139852818139852808162933760217678233603809369088045712429056380936908802176782336081629337601813985280181398528185752092672
1110883911681197230284859861514240179584542720359169085440502836719616502836719616359169085440179584542720598615142401197230284810883911682229025112064
12653034700878364164096431002902528143667634176032325217689605172034830336603404063539251720348303363232521768960143667634176043100290252878364164096653034700826748301344768
133918208204850936706662430562023997441120607546572828015188664320504273395957766723645279436867236452794368504273395957762801518866432011206075465728305620239974450936706662439182082048320979616137216
1423509249228832912948920322139341679820885573667192832235327584780288470655169560576705982754340864806837433532416705982754340864470655169560576235327584780288855736671928322139341679820832912948920322350924922883851755393646592
Technical details
Node id
n-895296f7b62fee9d · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-77a7ed3b1d5f257e

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 0)
  • 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:        3;
  1:       18,        18;
  2:      108,       216,        108;
  3:      648,      1944,       1944,        648;
  4:     3888,     15552,      23328,      15552,       3888;
  5:    23328,    116640,     233280,     233280,     116640,      23328;
  6:   139968,    839808,    2099520,    2799360,    2099520,     839808,     139968;
  7:   839808,   5878656,   17635968,   29393280,   29393280,   17635968,    5878656,     839808;
  8:  5038848,  40310784,  141087744,  282175488,  352719360,  282175488,  141087744,   40310784,   5038848;
  9: 30233088, 272097792, 1088391168, 2539579392, 3809369088, 3809369088, 2539579392, 1088391168, 272097792, 30233088;
%F Formula
The row polynomials satisfy P(n,x) = (6+6*x)*P(n-1,x) for n >= 1, with P(0,x) = 3.
%t Mathematica
P[0, x_] := 3;
P[n_, x_] := P[n, x] = Expand[(6 + 6*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] = 3; for(n = 1, N, my(i = n + 1); v[i] = (6 + 6*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.