a(n) = (1/5) * Sum_{k=0..n-1} binomial(5*n,5*k+1).
A387743
a(n) = (1/5) * Sum_{k=0..n-1} binomial(5*n,5*k+1).
Terms
- a(0) =0a(1) =1a(2) =44a(3) =1277a(4) =42317a(5) =1338030a(6) =42995667a(7) =1373879453a(8) =43986122004
External references
- oeis: A387743