A356546 → basis A013611 → x ↦ x/(x+1)

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in [−1, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(n + n x\right)\,P_{n}(x) = \left(-4 - 16\,x - 12\,x^{2} + 8\,n + 32\,n x + 24\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
141216
224144216384
316014404320432010240
41120134406048012096090720286720
580641209607257602177280326592019595528257536
6591361064448798336031933440718502408622028843110144242221056
74392969225216830269444151347201245404160224172748822417274889607403527197425664
Technical details
Node id
n-ade3cf4243d09b7b · revision 0 · JSON
Definition source
derived:mobius_x_over_x_plus_one
Fingerprint
f6-f9762973ec1089d7

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:        4,        12;
  2:       24,       144,        216;
  3:      160,      1440,       4320,        4320;
  4:     1120,     13440,      60480,      120960,        90720;
  5:     8064,    120960,     725760,     2177280,      3265920,      1959552;
  6:    59136,   1064448,    7983360,    31933440,     71850240,     86220288,      43110144;
  7:   439296,   9225216,   83026944,   415134720,   1245404160,   2241727488,    2241727488,     960740352;
  8:  3294720,  79073280,  830269440,  4981616640,  18681062400,  44834549760,   67251824640,   57644421120,   21616657920;
  9: 24893440, 672122880, 8065474560, 56458321920, 254062448640, 762187345920, 1524374691840, 1959910318080, 1469932738560, 489977579520;
%F Formula
The row polynomials satisfy (n+n*x)*P(n,x) = (8*n-4+(32*n-16)*x+(24*n-12)*x^2)*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[Together[((8*n - 4 + (32*n - 16)*x + (24*n - 12)*x^2)*P[n - 1, x])/(n + n*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] = ((8*n - 4 + (32*n - 16)*x + (24*n - 12)*x^2)*v[i - 1])/(n + n*x)); 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.