A196347 → θ+1

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1123
228616
36365424120
4241924323841201152
5120120036004800300072013440
67208640324005760054000259205040184320
7504070560317520705600882000635040246960403202903040
8403206451203386880903168014112000135475207902720258048036288051609600
93628806531840391910401219276802286144002743372802133734401045094402939328036288001021870080
103628800725760004898880001741824000381024000054867456005334336000348364800014696640003628800003991680022295347200
11399168008781696006586272000263450880006586272000011064936960012909093120010538035200059276448000219542400004829932800479001600531372441600
12479001600114960384009484231680042152140800011855289600002276215603200309818234880030349541376002133952128000105380352000034775516160068976230400622702080013733933875200
13622702080016190254080014571228672007123711795200222615993600004808505461760074798973849600854845415424007212758192640044523198720000195902074368005828491468800105236651520087178291200382588157952000
14871782912002440992153600237996734976001269315919872004363273474560001047185633894400183257485931520023935671631872002356167676262400174530938982400095992016440320038079477596160010313191848960017086945075200130767436800011426632984166400
Technical details
Node id
n-bf0d178eef6b2fcb · revision 0 · JSON
Definition source
derived:theta_plus_one
Fingerprint
f6-e99c3824c4864868

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:      1,       2;
  2:      2,       8,        6;
  3:      6,      36,       54,        24;
  4:     24,     192,      432,       384,       120;
  5:    120,    1200,     3600,      4800,      3000,       720;
  6:    720,    8640,    32400,     57600,     54000,     25920,      5040;
  7:   5040,   70560,   317520,    705600,    882000,    635040,    246960,     40320;
  8:  40320,  645120,  3386880,   9031680,  14112000,  13547520,   7902720,   2580480,   362880;
  9: 362880, 6531840, 39191040, 121927680, 228614400, 274337280, 213373440, 104509440, 29393280, 3628800;
%F Formula
The row polynomials satisfy (1+n*x)*P(n,x) = (n+(n^2+2*n)*x+(n^2+n)*x^2)*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 + (n^2 + 2*n)*x + (n^2 + n)*x^2)*P[n - 1, x])/(1 + n*x)]];
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 + (n^2 + 2*n)*x + (n^2 + n)*x^2)*v[i - 1])/(1 + n*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.