a(1)=2, a(n) = (4n/3)*(2n-1)!! (see A001147) for n>1.
A208124
a(1)=2, a(n) = (4n/3)*(2n-1)!! (see A001147) for n>1.
Terms
- a(0) =2a(1) =8a(2) =60a(3) =560a(4) =6300a(5) =83160a(6) =1261260a(7) =21621600a(8) =413513100a(9) =8729721000a(10) =201656555100
External references
- oeis: A208124