Ceiling(Gamma(n/4)).

Terms

a(0) =4a(1) =2a(2) =2a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =2a(9) =2a(10) =2a(11) =2a(12) =3a(13) =4a(14) =5a(15) =6a(16) =9a(17) =12a(18) =17a(19) =24a(20) =36a(21) =53a(22) =79a(23) =120a(24) =185a(25) =288a(26) =454a(27) =720a(28) =1156a(29) =1872