a(n) = (2^(n-1)/n!) * Product_{k=1..n-1} (2^k-1).
A091669
a(n) = (2^(n-1)/n!) * Product_{k=1..n-1} (2^k-1).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =7a(4) =42a(5) =434a(6) =7812a(7) =248031a(8) =14055090a(9) =1436430198a(10) =267176016828
External references
- oeis: A091669