A156992 → basis A013609 → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(4 + 6\,x + 4\,n + 6\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
181220
296288216600
31536691210368518424000
4307201843204147204147201555201200000
57372805529600165888002488320018662400559872072000000
620643840185794560696729600139345920015676416009405849602351462405040000000
7660602880693633024031213486080780337152001170505728001053455155205267275776011287019520403200000000
Technical details
Node id
n-9b745660022bc455 · revision 0 · JSON
Definition source
derived:basis_map_A013610
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 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:            8,             12;
  2:           96,            288,            216;
  3:         1536,           6912,          10368,            5184;
  4:        30720,         184320,         414720,          414720,          155520;
  5:       737280,        5529600,       16588800,        24883200,        18662400,         5598720;
  6:     20643840,      185794560,      696729600,      1393459200,      1567641600,       940584960,       235146240;
  7:    660602880,     6936330240,    31213486080,     78033715200,    117050572800,    105345515520,     52672757760,     11287019520;
  8:  23781703680,   285380444160,  1498247331840,   4494741995520,   8427641241600,  10113169489920,   7584877117440,   3250661621760,    609499054080;
  9: 951268147200, 12842119987200, 77052719923200, 269684519731200, 606790169395200, 910185254092800, 910185254092800, 585119091916800, 219419659468800, 36569943244800;
%F Formula
The row polynomials satisfy P(n,x) = (4*n+4+(6*n+6)*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[(4*n + 4 + (6*n + 6)*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] = (4*n + 4 + (6*n + 6)*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.