A038338 → basis A013609 → θ+1

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + 2\,x + n x\right)\,P_{n}(x) = \left(24 + 96\,x + 72\,x^{2} + 24\,n x + 24\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 576 + 2304\,x + 1728\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
0576230417284608
1138248294412441655296276480
2331776265420859719685308416165888015925248
379626247962624023887872031850496019906560047775744891813888
41911029762293235712859963392015288238080143327232006879707136133772083248922361856
5458647142464210599936288947699712642105999360802632499200577895399424224737099776366917713922641807540224
611007531417617612050268169246326390784246568703754243852635996160036985305563136215747615784967044820107264990677827584140896402145280
7264180754022447552535724032285315214344192887647333515264166433875034112019972065004093441553382833651712760840571584512213986410758144264180754022407439330033270784
Technical details
Node id
n-9c4e830626e0fc99 · revision 0 · JSON
Definition source
derived:theta_plus_one
Fingerprint
f6-e99c3824c4864868

Observed on the stored rows ?

  • Degrees: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (affine: slope 1, intercept 2)
  • 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:              576,              2304,               1728;
  1:            13824,             82944,             124416,               55296;
  2:           331776,           2654208,            5971968,             5308416,             1658880;
  3:          7962624,          79626240,          238878720,           318504960,           199065600,            47775744;
  4:        191102976,        2293235712,         8599633920,         15288238080,         14332723200,          6879707136,          1337720832;
  5:       4586471424,       64210599936,       288947699712,        642105999360,        802632499200,        577895399424,        224737099776,         36691771392;
  6:     110075314176,     1761205026816,      9246326390784,      24656870375424,      38526359961600,      36985305563136,      21574761578496,       7044820107264,        990677827584;
  7:    2641807540224,    47552535724032,    285315214344192,     887647333515264,    1664338750341120,    1997206500409344,    1553382833651712,     760840571584512,     213986410758144,     26418075402240;
  8:   63403380965376,  1268067619307520,   8559456430325760,   30433622863380480,   66573550013644800,   95865912019648512,   93202970019102720,   60867245726760960,   25678369290977280,   6340338096537600,    697437190619136;
  9: 1521681143169024, 33476985149718528, 251077388622888960, 1004309554491555840, 2510773886228889600, 4218100128864534528, 4921116817008623616, 4017238217966223360, 2259696497606000640, 836924628742963200, 184123418323451904, 18260173718028288;
%F Formula
The row polynomials satisfy (1+(n+2)*x)*P(n,x) = (24+(24*n+96)*x+(24*n+72)*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 576 + 2304*x + 1728*x^2.
%t Mathematica
P[0, x_] := 576 + 2304*x + 1728*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((24 + (24*n + 96)*x + (24*n + 72)*x^2)*P[n - 1, x])/(1 + (n + 2)*x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 576 + 2304*x + 1728*x^2; for(n = 1, N, my(i = n + 1); v[i] = ((24 + (24*n + 96)*x + (24*n + 72)*x^2)*v[i - 1])/(1 + (n + 2)*x)); 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.