a(n) = Sum_{k=0..n} (-9)^k * binomial(-1/3,k) * binomial(n*k,n-k).
A361846
a(n) = Sum_{k=0..n} (-9)^k * binomial(-1/3,k) * binomial(n*k,n-k).
Terms
- a(0) =1a(1) =3a(2) =24a(3) =243a(4) =2973a(5) =41676a(6) =652662a(7) =11228556a(8) =209674050a(9) =4211011422a(10) =90309000630
External references
- oeis: A361846