A038329 → x ↦ x+1 → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(18 + 9\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 324 + 324\,x + 81\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
032432481729
158328748437472919683
2104976209952157464524886561531441
318895684723920472392023619605904905904914348907
43401222410203667212754584085030560318864606377292531441387420489
5612220032214277011232141551682678462640133923132040176939666961566478296910460353203
6110199605764407984230477139724032771397240324821232752019284931008482123275268874753643046721282429536481
71983592903688926168066561785233613312208277254886415620794116487810397058242603465686085578855041669735688023874204897625597484987
Technical details
Node id
n-5b0c1f0fe75b55a7 · revision 0 · JSON
Definition source
derived:basis_map_A013610
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

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:            324,             324,              81;
  1:           5832,            8748,            4374,              729;
  2:         104976,          209952,          157464,            52488,             6561;
  3:        1889568,         4723920,         4723920,          2361960,           590490,           59049;
  4:       34012224,       102036672,       127545840,         85030560,         31886460,         6377292,          531441;
  5:      612220032,      2142770112,      3214155168,       2678462640,       1339231320,       401769396,        66961566,         4782969;
  6:    11019960576,     44079842304,     77139724032,      77139724032,      48212327520,     19284931008,      4821232752,       688747536,       43046721;
  7:   198359290368,    892616806656,   1785233613312,    2082772548864,    1562079411648,    781039705824,    260346568608,     55788550416,     6973568802,     387420489;
  8:  3570467226624,  17852336133120,  40167756299520,   53557008399360,   46862382349440,  28117429409664,  11715595587360,   3347313024960,   627621192180,   69735688020,   3486784401;
  9: 64268410079232, 353476255435776, 883690638589440, 1325535957884160, 1325535957884160, 927875170518912, 463937585259456, 165691994735520, 41422998683880, 6903833113980, 690383311398, 31381059609;
%F Formula
The row polynomials satisfy P(n,x) = (18+9*x)*P(n-1,x) for n >= 1, with P(0,x) = 324 + 324*x + 81*x^2.
%t Mathematica
P[0, x_] := 324 + 324*x + 81*x^2;
P[n_, x_] := P[n, x] = Expand[(18 + 9*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] = 324 + 324*x + 81*x^2; for(n = 1, N, my(i = n + 1); v[i] = (18 + 9*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.