a(n) = 2^(n-1)*(2^n - 1)*Product_{j=1..n-1} (2^j + 1).
A005477
a(n) = 2^(n-1)*(2^n - 1)*Product_{j=1..n-1} (2^j + 1).
Terms
- a(0) =0a(1) =1a(2) =18a(3) =420a(4) =16200a(5) =1138320a(6) =152681760a(7) =40012315200
External references
- oeis: A005477
A005477
a(n) = 2^(n-1)*(2^n - 1)*Product_{j=1..n-1} (2^j + 1).