A085881 → basis A013609 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(-4 - 4\,x + 8\,n + 8\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
1448
2489648192
3960288028809607680
42688010752016128010752026880430080
5967680483840096768009676800483840096768030965760
642577920255467520638668800851558400638668800255467520425779202724986880
722140518401549836288046495088640774918144007749181440046495088640154983628802214051840283398635520
Technical details
Node id
n-eeff530c34f1e7bf · 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:             1;
  1:             4,              4;
  2:            48,             96,              48;
  3:           960,           2880,            2880,             960;
  4:         26880,         107520,          161280,          107520,            26880;
  5:        967680,        4838400,         9676800,         9676800,          4838400,           967680;
  6:      42577920,      255467520,       638668800,       851558400,        638668800,        255467520,        42577920;
  7:    2214051840,    15498362880,     46495088640,     77491814400,      77491814400,      46495088640,     15498362880,      2214051840;
  8:  132843110400,  1062744883200,   3719607091200,   7439214182400,    9299017728000,    7439214182400,   3719607091200,   1062744883200,   132843110400;
  9: 9033331507200, 81299983564800, 325199934259200, 758799846604800, 1138199769907200, 1138199769907200, 758799846604800, 325199934259200, 81299983564800, 9033331507200;
%F Formula
The row polynomials satisfy P(n,x) = (8*n-4+(8*n-4)*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[(8*n - 4 + (8*n - 4)*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] = (8*n - 4 + (8*n - 4)*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.