A135089 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1101020
220402080
34012012040320
480320480320801280
5160800160016008001605120
63201920480064004800192032020480
7640448013440224002240013440448064081920
81280102403584071680896007168035840102401280327680
925602304092160215040322560322560215040921602304025601310720
105120512002304006144001075200129024010752006144002304005120051205242880
11102401126405632001689600337920047308804730880337920016896005632001126401024020971520
1220480245760135168045056001013760016220160189235201622016010137600450560013516802457602048083886080
134096053248031948801171456029286400527155207028736070287360527155202928640011714560319488053248040960335544320
1481920114688074547202981888082001920164003840246005760281149440246005760164003840820019202981888074547201146880819201342177280
Technical details
Node id
n-9483623b407aaab0 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-77a7ed3b1d5f257e

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: 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:    1;
  1:   10,    10;
  2:   20,    40,    20;
  3:   40,   120,   120,     40;
  4:   80,   320,   480,    320,     80;
  5:  160,   800,  1600,   1600,    800,    160;
  6:  320,  1920,  4800,   6400,   4800,   1920,    320;
  7:  640,  4480, 13440,  22400,  22400,  13440,   4480,   640;
  8: 1280, 10240, 35840,  71680,  89600,  71680,  35840, 10240,  1280;
  9: 2560, 23040, 92160, 215040, 322560, 322560, 215040, 92160, 23040, 2560;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n-2+(2*n-2)*x)*P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 10 + 10*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 10 + 10*x;
P[n_, x_] := P[n, x] = Expand[Together[((2*n - 2 + (2*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] = 1; v[2] = 10 + 10*x; for(n = 2, N, my(i = n + 1); v[i] = ((2*n - 2 + (2*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.