a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n,k) * binomial(n+4,k).
A388411
a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n,k) * binomial(n+4,k).
Terms
- a(0) =1a(1) =8a(2) =60a(3) =440a(4) =3199a(5) =23184a(6) =167880a(7) =1215960a(8) =8813970a(9) =63952240a(10) =464525672a(11) =3377839920a(12) =24588537995a(13) =179172439840
External references
- oeis: A388411