basis-map coefficients of A026729, shifted → θ+1 → basis A013611

only rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
2-2-8-10
33244875
4-4-48-192-256-500
5580480128012803125
6-6-120-960-3840-7680-6144-18750
7716816808960268804300828672109375
8-8-224-2688-17920-71680-172032-229376-131072-625000
Technical details
Node id
n-9b654d570e0f3f5e · revision 0 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-03d7b8417365c509

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,   -8;
   3:   3,   24,    48;
   4:  -4,  -48,  -192,   -256;
   5:   5,   80,   480,   1280,    1280;
   6:  -6, -120,  -960,  -3840,   -7680,    -6144;
   7:   7,  168,  1680,   8960,   26880,    43008,    28672;
   8:  -8, -224, -2688, -17920,  -71680,  -172032,  -229376,  -131072;
   9:   9,  288,  4032,  32256,  161280,   516096,  1032192,  1179648,   589824;
  10: -10, -360, -5760, -53760, -322560, -1290240, -3440640, -5898240, -5898240, -2621440;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = -(n+4*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 + 4*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 + 4*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.