a(n) = Sum_{d|n, d==1 mod 4} d^6 - Sum_{d|n, d==3 mod 4} d^6.

Terms

a(0) =1a(1) =1a(2) =-728a(3) =1a(4) =15626a(5) =-728a(6) =-117648a(7) =1a(8) =530713a(9) =15626a(10) =-1771560a(11) =-728a(12) =4826810a(13) =-117648a(14) =-11375728a(15) =1a(16) =24137570a(17) =530713a(18) =-47045880a(19) =15626a(20) =85647744a(21) =-1771560a(22) =-148035888a(23) =-728a(24) =244156251a(25) =4826810a(26) =-386889776a(27) =-117648a(28) =594823322a(29) =-11375728