a(n) = Sum_{d|n, n/d=1 mod 4} d^4.

Terms

a(0) =1a(1) =16a(2) =81a(3) =256a(4) =626a(5) =1296a(6) =2401a(7) =4096a(8) =6562a(9) =10016a(10) =14641a(11) =20736a(12) =28562a(13) =38416a(14) =50706a(15) =65536a(16) =83522a(17) =104992a(18) =130321a(19) =160256a(20) =194482a(21) =234256a(22) =279841a(23) =331776a(24) =391251a(25) =456992a(26) =531522a(27) =614656a(28) =707282a(29) =811296