A178820 → basis A007318 → basis A013610

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1121224
29018090360
3540162016205404320
42835113401701011340283545360
513608680401360801360806804013608435456
6612363674169185401224720918540367416612363919104
726244018370805511240918540091854005511240183708026244033592320
810825658660520303118206062364075779550606236403031182086605201082565277136640
94330260389723401558893603637418405456127605456127603637418401558893603897234043302602217093120
1016888014168880140759960630202656168035464829404255779528354648294020265616807599606301688801401688801417293326336
11644815087092965883546482940106394488202127889764029790456696297904566962127889764010639448820354648294070929658864481508132058128384
122418056552901667860159591732305319724410011969379922519151007876022342842522019151007876011969379922553197244100159591732302901667860241805655990435962880
138928208801160667144069640028640255346771680638366929200114906047256015320806300801532080630080114906047256063836692920025534677168069640028640116066714408928208807313988648960
14325241892045533864880295970121720118388048688032556713389206511342677840976701401676011162301733440976701401676065113426778403255671338920118388048688029597012172045533864880325241892053287631585280
Technical details
Node id
n-517715329d52321c · revision 0 · JSON
Definition source
derived:basis_map_A013610
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:      12,       12;
  2:      90,      180,        90;
  3:     540,     1620,      1620,       540;
  4:    2835,    11340,     17010,     11340,      2835;
  5:   13608,    68040,    136080,    136080,     68040,     13608;
  6:   61236,   367416,    918540,   1224720,    918540,    367416,     61236;
  7:  262440,  1837080,   5511240,   9185400,   9185400,   5511240,   1837080,    262440;
  8: 1082565,  8660520,  30311820,  60623640,  75779550,  60623640,  30311820,   8660520,  1082565;
  9: 4330260, 38972340, 155889360, 363741840, 545612760, 545612760, 363741840, 155889360, 38972340, 4330260;
%F Formula
The row polynomials satisfy n*P(n,x) = (3*n+9+(3*n+9)*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 + (3*n + 9)*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 + (3*n + 9)*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.