A136572 → (θ+1)² → basis A008277

nonnegative coefficients

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1448
218541890
396672576961440
4600900015000600060031200
54320133920388800280800648004320876960
6352802222640106192801234800049392007408803528030940560
7322560409651203115929605486745603386880008580096090316803225601335398400
832659208328096009879408000253761984002270140992086416243201508855040117573120326592069064410240
9362880001854316800033856704000012376022400001543147200000828346176000213373440000272160000001632960000362880004208500800000
1043908480044918375040012514355884800639966096000001083353927040007881001349760028095719097600521632742400050714294400024149664000439084800297949772736000
1157480192001176619530240049735310929920035149194888192007928817684480000760837711011840036062842540032009140902493184001280371276800009800372736000379369267200574801920024219836457062400
1280951270400331495452288000211788761184000002050115208261120006078226947496704007545720481947648004626708336746496001537760046670848002910214361134080031834087084800001967925383424006314199091200809512704002237852294642764800
1312204960768009997083365068800962934789712896000126830840036060160004891142299512268800077423844372921446400602061927113687040002552340451678617600062674060188579840009187308628033536008063329380986880041094102905856001110651429888001220496076800232991873564779929600
141961511552000032135443756416000046587880486667520000830816852209344000000413421748359459840000082519471483818969600008017508464593788160000424918010644807680000013167330860331648000002483793425393280000002902013187929856000020884213494144000008924877561600000020595871296000001961511552000027126891619546118400000
Technical details
Node id
n-3e937a723b98e416 · revision 0 · JSON
Definition source
derived:basis_map_A008277
Fingerprint
f6-4732d0911d5a78c5

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): no

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:        1;
  1:        4,           4;
  2:       18,          54,           18;
  3:       96,         672,          576,            96;
  4:      600,        9000,        15000,          6000,           600;
  5:     4320,      133920,       388800,        280800,         64800,         4320;
  6:    35280,     2222640,     10619280,      12348000,       4939200,       740880,        35280;
  7:   322560,    40965120,    311592960,     548674560,     338688000,     85800960,      9031680,      322560;
  8:  3265920,   832809600,   9879408000,   25376198400,   22701409920,   8641624320,   1508855040,   117573120,    3265920;
  9: 36288000, 18543168000, 338567040000, 1237602240000, 1543147200000, 828346176000, 213373440000, 27216000000, 1632960000, 36288000;
%F Formula
The row polynomials satisfy n*P(n,x) = (n^2+2*n+1+(n^2+2*n+1)*x)*P(n-1,x) + (n^2+2*n+1)*x*d/dx 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[((n^2 + 2*n + 1 + (n^2 + 2*n + 1)*x)*P[n - 1, x] + (n^2 + 2*n + 1)*x*D[P[n - 1, x], 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] = ((n^2 + 2*n + 1 + (n^2 + 2*n + 1)*x)*v[i - 1] + (n^2 + 2*n + 1)*x*deriv(v[i - 1], x))/(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

  • Real-rooted? Every row P_n, n ≥ 0, is zero or real-rooted with all roots in (−∞, 0]
  • Coefficients of one sign? Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
    derived from Ray basis map theorem
  • Hadamard kernel (Malo)? Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
    derived from Ray basis map theorem

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. [MW08] Shi-Mei Ma and Yi Wang. q-Eulerian polynomials and polynomials with only real zeros. The Electronic Journal of Combinatorics, 15(1):Research Paper 17, January 2008. doi:10.37236/741
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.