a(n) = Sum_{k=0..n} (-1)^k * binomial(4*n-k-1,n-k).
A371814
a(n) = Sum_{k=0..n} (-1)^k * binomial(4*n-k-1,n-k).
Terms
- a(0) =1a(1) =2a(2) =16a(3) =128a(4) =1068a(5) =9142a(6) =79612a(7) =701864a(8) =6244892a(9) =55962920a(10) =504375396a(11) =4567003520a(12) =41513817444a(13) =378596616452
External references
- oeis: A371814