a(n) = Sum_{k=0..n} (-3)^(n-k) * binomial(5*n,k).
A386702
a(n) = Sum_{k=0..n} (-3)^(n-k) * binomial(5*n,k).
Terms
- a(0) =1a(1) =2a(2) =24a(3) =248a(4) =2676a(5) =29562a(6) =331956a(7) =3771896a(8) =43242660a(9) =499215146a(10) =5795429764a(11) =67587697872a(12) =791232339756
External references
- oeis: A386702