A258758 → D

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(-2 - 2\,x + 4\,n + 4\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
111
26612
3306030120
41404204201401120
563025203780252063010080
6277213860277202772013860277288704
712012720721801802402401801807207212012768768
8514803603601081080180180018018001081080360360514806589440
9218790175032061261201225224015315300122522406126120175032021879056010240
109237808314020332560807759752011639628011639628077597520332560808314020923780472975360
113879876387987601745944204655851208147739609777287528147739604655851201745944203879876038798763972993024
12162249361784742968923714802677114440535422888074959204327495920432535422888026771144408923714801784742961622493633228668928
1367603900811246800446185740014872858000334639305005354228880062466003600535422888003346393050014872858000446185740081124680067603900276905574400
1428081620036506106002190366360080313433200200783583000361410449400481880599200481880599200361410449400200783583000803134332002190366360036506106002808162002300446310400
Technical details
Node id
n-115607f387733cce · 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:      1;
  2:      6,       6;
  3:     30,      60,      30;
  4:    140,     420,     420,      140;
  5:    630,    2520,    3780,     2520,      630;
  6:   2772,   13860,   27720,    27720,    13860,     2772;
  7:  12012,   72072,  180180,   240240,   180180,    72072,   12012;
  8:  51480,  360360, 1081080,  1801800,  1801800,  1081080,  360360,   51480;
  9: 218790, 1750320, 6126120, 12252240, 15315300, 12252240, 6126120, 1750320, 218790;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (4*n-2+(4*n-2)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 1.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((4*n - 2 + (4*n - 2)*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] = 1; for(n = 2, N, my(i = n + 1); v[i] = ((4*n - 2 + (4*n - 2)*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.