a(n) = A139315(n)*n.

Terms

a(0) =2a(1) =6a(2) =24a(3) =60a(4) =360a(5) =840a(6) =10080a(7) =7560a(8) =0a(9) =27720a(10) =332640a(11) =720720a(12) =0a(13) =10810800a(14) =17297280a(15) =36756720a(16) =1102701600a(17) =698377680a(18) =27935107200a(19) =48886437600a(20) =0a(21) =16062686640a(22) =385504479360a(24) =0a(28) =0