a(n) = Sum_{k=0..n} binomial(4*n+1,5*k).

A387873

a(n) = Sum_{k=0..n} binomial(4*n+1,5*k).

Terms

    a(0) =1a(1) =2a(2) =127a(3) =1574a(4) =25773a(5) =427351a(6) =6643782a(7) =107746282a(8) =1717012749a(9) =27481113638a(10) =439924466026

External references