a(n) = Sum_{k=0..n} binomial(n,k)^3 * 6^k.
A216698
a(n) = Sum_{k=0..n} binomial(n,k)^3 * 6^k.
Terms
- a(0) =1a(1) =7a(2) =85a(3) =1351a(4) =23281a(5) =422527a(6) =7951069a(7) =153458935a(8) =3018043777a(9) =60225528727
External references
- oeis: A216698