a(n) = Sum_{k=0..n} (-1)^k * binomial(-3,k) * binomial(n*k,n-k).
A362085
a(n) = Sum_{k=0..n} (-1)^k * binomial(-3,k) * binomial(n*k,n-k).
Terms
- a(0) =1a(1) =3a(2) =12a(3) =55a(4) =315a(5) =2106a(6) =15946a(7) =134730a(8) =1253637a(9) =12702961a(10) =138955146a(11) =1629581955a(12) =20371061009a(13) =270124999977
External references
- oeis: A362085