A085881 → basis A013611 → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(-6 - 8\,x + 12\,n + 16\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
16814
2108288192588
332401296017280768041160
4136080725760145152012902404300804033680
573483204898880013063680017418240011612160030965760508243680
6484989120387991296012933043200229920768002299207680012262440960272498688078269526720
7378291513603530720793601412288317440313841848320041845579776003347646382080148784283648028339863552014245053863040
Technical details
Node id
n-910ba4510ca288b7 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-c91d5d506c107735

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: 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:               1;
  1:               6,                8;
  2:             108,              288,               192;
  3:            3240,            12960,             17280,              7680;
  4:          136080,           725760,           1451520,           1290240,             430080;
  5:         7348320,         48988800,         130636800,         174182400,          116121600,           30965760;
  6:       484989120,       3879912960,       12933043200,       22992076800,        22992076800,        12262440960,         2724986880;
  7:     37829151360,     353072079360,     1412288317440,     3138418483200,      4184557977600,      3347646382080,      1487842836480,      283398635520;
  8:   3404623622400,   36315985305600,   169474598092800,   451932261580800,    753220435968000,    803435131699200,    535623421132800,   204047017574400,    34007836262400;
  9: 347271609484800, 4167259313817600, 22225383007027200, 69145636021862400, 138291272043724800, 184388362724966400, 163900766866636800, 93657581066649600, 31219193688883200, 4625065731686400;
%F Formula
The row polynomials satisfy P(n,x) = (12*n-6+(16*n-8)*x)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[(12*n - 6 + (16*n - 8)*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] = 1; for(n = 1, N, my(i = n + 1); v[i] = (12*n - 6 + (16*n - 8)*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.