a(n) = Sum_{k=0..n} (-1)^k * binomial(5*n-k+2,n-k).
A390548
a(n) = Sum_{k=0..n} (-1)^k * binomial(5*n-k+2,n-k).
Terms
- a(0) =1a(1) =6a(2) =56a(3) =574a(4) =6157a(5) =67826a(6) =760384a(7) =8630926a(8) =98877509a(9) =1140897484a(10) =13239577408a(11) =154356072202
External references
- oeis: A390548