A156992 → D

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
122
2121224
37214472288
4480144014404803840
53600144002160014400360057600
63024015120030240030240015120030240967680
72822401693440423360056448004233600169344028224018063360
82903040203212806096384010160640010160640060963840203212802903040371589120
932659200261273600914457600182891520022861440001828915200914457600261273600326592008360755200
1039916800035925120001437004800033530112000502951680005029516800033530112000143700480003592512000399168000204374016000
115269017600526901760002371057920006322821120001106493696000132779243520011064936960006322821120002371057920005269017600052690176005395474022400
12747242496008219667456004109833728000123295011840002465900236800034522603315200345226033152002465900236800012329501184000410983372800082196674560074724249600153035263180800
13113331778560013599813427200747989738496002493299128320005609923038720008975876861952001047185633894400897587686195200560992303872000249329912832000747989738496001359981342720011333177856004642069649817600
1418307441152000237996734976000142798040985600052359281694720001308982042368000023561676762624000314155690168320003141556901683200023561676762624000130898204236800005235928169472000142798040985600023799673497600018307441152000149974557917184000
Technical details
Node id
n-c0d162a3ff50a265 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-77a7ed3b1d5f257e

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: yes
  • γ-positive (gamma_positive): yes
  • 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:        2;
  2:       12,        12;
  3:       72,       144,        72;
  4:      480,      1440,      1440,        480;
  5:     3600,     14400,     21600,      14400,       3600;
  6:    30240,    151200,    302400,     302400,     151200,      30240;
  7:   282240,   1693440,   4233600,    5644800,    4233600,    1693440,    282240;
  8:  2903040,  20321280,  60963840,  101606400,  101606400,   60963840,  20321280,   2903040;
  9: 32659200, 261273600, 914457600, 1828915200, 2286144000, 1828915200, 914457600, 261273600, 32659200;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (n^2+n+(n^2+n)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 2.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 2;
P[n_, x_] := P[n, x] = Expand[Together[((n^2 + n + (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] = 2; for(n = 2, N, my(i = n + 1); v[i] = ((n^2 + n + (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.