Number of even divisors of n!.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =6a(5) =12a(6) =24a(7) =48a(8) =84a(9) =140a(10) =240a(11) =480a(12) =720a(13) =1440a(14) =2376a(15) =3696a(16) =5040a(17) =10080a(18) =13824a(19) =27648a(20) =38880a(21) =57600a(22) =91200a(23) =182400a(24) =232320a(25) =325248a(26) =510048a(27) =649152a(28) =882000a(29) =1764000