a(n) = [n/2]!*[(n+1)/2]!*C([n/2],2)*C([(n+1)/2],2).
A226283
a(n) = [n/2]!*[(n+1)/2]!*C([n/2],2)*C([(n+1)/2],2).
Terms
- a(0) =0a(1) =0a(2) =0a(3) =4a(4) =36a(5) =324a(6) =2592a(7) =20736a(8) =172800a(9) =1440000a(10) =12960000a(11) =116640000a(12) =1143072000a(13) =11202105600a(14) =119489126400
External references
- oeis: A226283