Sum of even divisors of !n.

Terms

a(0) =0a(1) =0a(2) =0a(3) =2a(4) =0a(5) =72a(6) =0a(7) =2704a(8) =0a(9) =268128a(10) =0a(11) =17621496a(12) =0a(13) =4974281208a(14) =0a(15) =549790303712a(16) =0a(18) =0a(20) =0a(22) =0a(24) =0a(26) =0a(28) =0a(30) =0