basis-map coefficients of A026729 → D → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
10
211
3246
43121227
54244832108
654012016080405
76602404804801921458
87844201120168013444485103
981126722240448053763584102417496
109144100840321008016128161289216230459049
11101801440672020160403205376046080230405120196830
121122019801056036960887041478401689601267205632011264649539
131226426401584063360177408354816506880506880337920135168245762125764
1413312343222880102960329472768768131788816473601464320878592319488532486908733
151436443683203216016057657615375363075072461260851251204100096223641674547211468822320522
Technical details
Node id
n-86d2e7430fa8b666 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-11aec07ce60b6d61

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 -2)
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1: 0;
   2: 1;
   3: 2,   4;
   4: 3,  12,   12;
   5: 4,  24,   48,   32;
   6: 5,  40,  120,  160,    80;
   7: 6,  60,  240,  480,   480,   192;
   8: 7,  84,  420, 1120,  1680,  1344,   448;
   9: 8, 112,  672, 2240,  4480,  5376,  3584, 1024;
  10: 9, 144, 1008, 4032, 10080, 16128, 16128, 9216, 2304;
%F Formula
The row polynomials satisfy (n-2)*P(n,x) = (n-1+(2*n-2)*x)*P(n-1,x) for n >= 3, with P(1,x) = 0, P(2,x) = 1.
%t Mathematica
P[1, x_] := 0;
P[2, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n - 1 + (2*n - 2)*x)*P[n - 1, x])/(n - 2)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 0; v[2] = 1; for(n = 3, N, my(i = n); v[i] = ((n - 1 + (2*n - 2)*x)*v[i - 1])/(n - 2)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.