a(n) = Sum_{d|n, n/d=3 mod 4} d^4.

Terms

a(0) =0a(1) =0a(2) =1a(3) =0a(4) =0a(5) =16a(6) =1a(7) =0a(8) =81a(9) =0a(10) =1a(11) =256a(12) =0a(13) =16a(14) =626a(15) =0a(16) =0a(17) =1296a(18) =1a(19) =0a(20) =2482a(21) =16a(22) =1a(23) =4096a(24) =0a(25) =0a(26) =6562a(27) =256a(28) =0a(29) =10016