A120910 → D → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
133
2181230
38110836225
4324648432961500
512153240324014402409375
64374145801944012960432057656250
715309612361020609072045360120961344328125
8524882449444898885443203628801451523225630721875000
9177147944784220449629393282449440130636843545682944691210546875
105904903542940944784014696640146966409797760435456012441602073601536058593750
11194861712990780389723406928416080831520646652163592512013685760342144050688033792322265625
126377292467668081558893603117787204157049603879912962586608641231718404105728091238401216512737281757812500
132072619916580959260796850413510411202026561680216166579216812956169607403524003084801186099202372198428753921597449521484375
1466961566580333572232133428856743727049457287840113487454081008777369667251824643362591232124540416033210777660383232670924834406451269531250
Technical details
Node id
n-6b935edaa11ea35d · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-f06e51c139cfae05

Observed on the stored rows ?

  • Degrees: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (affine: slope 1, intercept -1)
  • 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:      0;
  1:      3;
  2:     18,     12;
  3:     81,    108,      36;
  4:    324,    648,     432,      96;
  5:   1215,   3240,    3240,    1440,     240;
  6:   4374,  14580,   19440,   12960,    4320,     576;
  7:  15309,  61236,  102060,   90720,   45360,   12096,   1344;
  8:  52488, 244944,  489888,  544320,  362880,  145152,  32256,  3072;
  9: 177147, 944784, 2204496, 2939328, 2449440, 1306368, 435456, 82944, 6912;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (3*n+2*n*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 3.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 3;
P[n_, x_] := P[n, x] = Expand[Together[((3*n + 2*n*x)*P[n - 1, x])/(n - 1)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = 3; for(n = 2, N, my(i = n + 1); v[i] = ((3*n + 2*n*x)*v[i - 1])/(n - 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.