a(n) = [x^n] (1/6 * Sum_{k=0..n} (k+3)!*x^k)^(1/2).
A303613
a(n) = [x^n] (1/6 * Sum_{k=0..n} (k+3)!*x^k)^(1/2).
Terms
- a(0) =1a(1) =2a(2) =8a(3) =44a(4) =300a(5) =2408a(6) =22056a(7) =225824a(8) =2547352a(9) =31322640a(10) =416442016a(11) =5948450912a(12) =90815006528
External references
- oeis: A303613