basis-map coefficients of A026729, shifted → θ+1 → basis A013610

only rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(-n - 3\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
2-2-6-8
33182748
4-4-36-108-108-256
55602705404051280
6-6-90-540-1620-2430-1458-6144
771269453780850510206510328672
8-8-168-1512-7560-22680-40824-40824-17496-131072
Technical details
Node id
n-1cf9b5e3408a7ce7 · revision 0 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-f9762973ec1089d7

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 -1)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • Nonnegative coefficients (nonn): no
  • 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:   1;
   2:  -2,   -6;
   3:   3,   18,    27;
   4:  -4,  -36,  -108,   -108;
   5:   5,   60,   270,    540,     405;
   6:  -6,  -90,  -540,  -1620,   -2430,   -1458;
   7:   7,  126,   945,   3780,    8505,   10206,    5103;
   8:  -8, -168, -1512,  -7560,  -22680,  -40824,  -40824,  -17496;
   9:   9,  216,  2268,  13608,   51030,  122472,  183708,  157464,   59049;
  10: -10, -270, -3240, -22680, -102060, -306180, -612360, -787320, -590490, -196830;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = -(n+3*n*x)*P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[(-(n + 3*n*x)*P[n - 1, x])/(n - 1)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = (-(n + 3*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, v[i])))};
T(10)

polytool c48629374597

Properties

Proof chains ? JSON

Same fingerprint ?

References

  1. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  2. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.