a(n) = Sum_{k=0..n} binomial(n,k)^3 * 3^k.
A206180
a(n) = Sum_{k=0..n} binomial(n,k)^3 * 3^k.
Terms
- a(0) =1a(1) =4a(2) =34a(3) =352a(4) =3946a(5) =46744a(6) =573616a(7) =7217536a(8) =92527738a(9) =1203467464a(10) =15834369244a(11) =210304283776
External references
- oeis: A206180