A178822 → x ↦ x+1 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(5 + 10\,x + n + 2\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
161218
2218484189
3563366724481512
4126100830244032201610206
52522520100802016020160806461236
6462554427720739201108808870429568336798
779211088665282217604435205322243548161013761732104
812872059214414457657614414402306304230630413178883294728444007
92002360362882881345344403603280720641076275292252164612608102502439405366
1030036006054054028828801009008024216192403603204612608034594560153753603075072177324147
1143689609696096057657602306304064576512129153024184504320184504320123002880492011528945664773778096
12618814851216336321089088049008960156828672365933568627314688784143360697016320418209792152076288253460483288556908
13856822276826732161960358498017920352864512940972032188194406428229160963136573440250925875213686865924562288647018905613660159464
1411628325584423259233860736186234048744936192223480857651081338888939234304119189790721191897907286683484164334174208133359206419051315255616363532
Technical details
Node id
n-3973b74c1ebdbd23 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-11aec07ce60b6d61

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:    6,    12;
  2:   21,    84,     84;
  3:   56,   336,    672,     448;
  4:  126,  1008,   3024,    4032,    2016;
  5:  252,  2520,  10080,   20160,   20160,    8064;
  6:  462,  5544,  27720,   73920,  110880,   88704,    29568;
  7:  792, 11088,  66528,  221760,  443520,  532224,   354816,  101376;
  8: 1287, 20592, 144144,  576576, 1441440, 2306304,  2306304, 1317888,  329472;
  9: 2002, 36036, 288288, 1345344, 4036032, 8072064, 10762752, 9225216, 4612608, 1025024;
%F Formula
The row polynomials satisfy n*P(n,x) = (n+5+(2*n+10)*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[((n + 5 + (2*n + 10)*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] = ((n + 5 + (2*n + 10)*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

Candidate equalities ?

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.