A178820 → basis A007318 → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(9 + 6\,x + 3\,n + 2\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
112820
29012040250
354010807201602500
4283575607560336056021875
513608453606048040320134401792175000
6612362449444082403628801814404838453761312500
72624401224720244944027216001814400725760161280153609375000
810825655773680134719201796256014968800798336026611205068804224064453125
943302602598156069284160107775360107775360718502403193344091238401520640112640429687500
10168880141125867603377602806004627207005398405604318723113510401186099202965248043929602928642792968750
1164481508472864392157621464031524292804203239040392302310426153487361245404160415134720922521601230028874547217773437500
1224180565519344452407092965880157621464002364321960025219434240196151155201120863744046702656001383782400276756480335462401863680111083984375
13892820880773778096030951123840756583027201260971712001513166054401345036492808966909952044834549760166053888004428103680805109760894566404587520683593750000
1432524189203035590992013154227632035077940352064309557312085746076416085746076416065330343936038109367296016937496576056458321920136868659202281144320233963520111411204150390625000
Technical details
Node id
n-000a80f5d182ab72 · revision 0 · JSON
Definition source
derived:reversal
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:      12,        8;
  2:      90,      120,       40;
  3:     540,     1080,      720,       160;
  4:    2835,     7560,     7560,      3360,       560;
  5:   13608,    45360,    60480,     40320,     13440,     1792;
  6:   61236,   244944,   408240,    362880,    181440,    48384,     5376;
  7:  262440,  1224720,  2449440,   2721600,   1814400,   725760,   161280,   15360;
  8: 1082565,  5773680, 13471920,  17962560,  14968800,  7983360,  2661120,  506880,   42240;
  9: 4330260, 25981560, 69284160, 107775360, 107775360, 71850240, 31933440, 9123840, 1520640, 112640;
%F Formula
The row polynomials satisfy n*P(n,x) = (3*n+9+(2*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[Together[((3*n + 9 + (2*n + 6)*x)*P[n - 1, x])/(n)]];
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] = ((3*n + 9 + (2*n + 6)*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 - 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.