a(n) = 4^n mod n^4.

Terms

a(0) =0a(1) =0a(2) =64a(3) =0a(4) =399a(5) =208a(6) =1978a(7) =0a(8) =6265a(9) =8576a(10) =6978a(11) =1792a(12) =19075a(13) =22864a(14) =36199a(15) =0a(16) =17089a(17) =87616a(18) =31867a(19) =107776a(20) =83791a(21) =142928a(22) =195688a(23) =225280a(24) =201999a(25) =302656a(26) =362152a(27) =304896a(28) =401393a(29) =546976