A085880 → basis A013611 → x ↦ x+1

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernelinterlacing (weak)

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(-36 - 24\,x + 24\,n + 16\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
26410
3729632200
41080216014403205000
5181444838448384215043584140000
632659210886401451520967680322560430084200000
76158592246343684105728036495360182476804866048540672132000000
8120092544560431872112086374412454041608302694403321077767380172870287364290000000
Technical details
Node id
n-f5981aa8f519188f · revision 0 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-f06e51c139cfae05

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 -1)
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:           1;
   2:           6,            4;
   3:          72,           96,           32;
   4:        1080,         2160,         1440,           320;
   5:       18144,        48384,        48384,         21504,          3584;
   6:      326592,      1088640,      1451520,        967680,        322560,        43008;
   7:     6158592,     24634368,     41057280,      36495360,      18247680,      4866048,       540672;
   8:   120092544,    560431872,   1120863744,    1245404160,     830269440,    332107776,     73801728,      7028736;
   9:  2401850880,  12809871360,  29889699840,   39852933120,   33210777600,  17712414720,   5904138240,   1124597760,    93716480;
  10: 48997757952, 293986547712, 783964127232, 1219499753472, 1219499753472, 812999835648, 361333260288, 103238074368, 17206345728, 1274544128;
%F Formula
The row polynomials satisfy n*P(n,x) = (24*n-36+(16*n-24)*x)*P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((24*n - 36 + (16*n - 24)*x)*P[n - 1, x])/(n)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = ((24*n - 36 + (16*n - 24)*x)*v[i - 1])/(n)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

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.