a(n) = (1/5) * Sum_{k=0..n-1} binomial(5*n,5*k+2).
A387744
a(n) = (1/5) * Sum_{k=0..n-1} binomial(5*n,5*k+2).
Terms
- a(0) =0a(1) =2a(2) =33a(3) =1399a(4) =40964a(5) =1353035a(6) =42829259a(7) =1375724946a(8) =43965655173
External references
- oeis: A387744