a(n) = Product_{i=1..n} (2^i - 1). Also called 2-factorial numbers.
A005329
a(n) = Product_{i=1..n} (2^i - 1). Also called 2-factorial numbers.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =21a(4) =315a(5) =9765a(6) =615195a(7) =78129765a(8) =19923090075
External references
- oeis: A005329