A385606 Diagonal of the rational function 1/(1 - (v^3 + w^3 + x^3 + y^3 + z^3 + v*w*x*y*z)).
1, 1, 1, 121, 721, 2521, 120121, 1262521, 7514641, 200655841, 2804296441, 23211542641, 443673670441, 7070369866561, 73192033638361, 1173608444069881, 19482750854113681, 235115468646608881, 3483568444035458401, 57574418930692099801, 769737183831483390601, 11118980118960559362001
Offset: 0
Keywords
Programs
-
PARI
a(n) = sum(k=0, n\3, (n+2*k)!/(k!^5*(n-3*k)!));
Formula
a(n) = Sum_{k=0..floor(n/3)} (n+2*k)!/(k!^5 * (n-3*k)!).