OFFSET
1,1
LINKS
David J. Gross and Vladimir Rosenhaus, The Bulk Dual of SYK: Cubic Couplings, arXiv:1702.08016 [hep-th], 2017, p. 33.
MATHEMATICA
t[n_, k_] := SeriesCoefficient[Sum[Binomial[n + j, j]^3 x^j, {j, 0, n + k}] (1 - x)^(3n + 1), {x, 0, k}];
a[n_] := t[2n, 2n - 1];
Array[a, 13] (* Jean-François Alcover, Feb 14 2019 *)
PROG
(Sage)
def a(n) :
R.<x> = QQ[]; p = 2*n; q = 2*n-1
return ((1-x)^(3*p+1) * sum(binomial(p+r, r)^3 * x^r for r in [0..p+q]))[q]
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric M. Schmidt, Oct 04 2017
STATUS
approved