a(0) = 0; a(n) = 5^(n-1) + (1/n) * Sum_{k=1..n-1} binomial(n,k)^2 * 5^(k-1) * (n-k) * a(n-k).
A333984
a(0) = 0; a(n) = 5^(n-1) + (1/n) * Sum_{k=1..n-1} binomial(n,k)^2 * 5^(k-1) * (n-k) * a(n-k).
Terms
- a(0) =0a(1) =1a(2) =7a(3) =82a(4) =1839a(5) =69630a(6) =3950650a(7) =313747050a(8) =33224570175
External references
- oeis: A333984