a(n) = (2^n/n!)*Product_{k=0..n-1} (4*k + 5).
A004985
a(n) = (2^n/n!)*Product_{k=0..n-1} (4*k + 5).
Terms
- a(0) =1a(1) =10a(2) =90a(3) =780a(4) =6630a(5) =55692a(6) =464100a(7) =3845400a(8) =31724550a(9) =260846300a(10) =2138939660a(11) =17500415400a(12) =142920059100
External references
- oeis: A004985