a(n) = n! * [x^n] Product_{k=1..n, gcd(n,k) = 1} (1 + x^k/k).
A338439
a(n) = n! * [x^n] Product_{k=1..n, gcd(n,k) = 1} (1 + x^k/k).
Terms
- a(0) =1a(1) =1a(2) =0a(3) =3a(4) =8a(5) =50a(6) =144a(7) =2394a(8) =8448a(9) =89424a(10) =576000a(11) =20124720a(12) =57231360a(13) =3213905760a(14) =11285084160a(15) =217204092000
External references
- oeis: A338439