Number of solutions to 1 +- 3 +- 6 +- ... +- n*(n+1)/2 == 0 mod n.

Terms

a(0) =1a(1) =2a(2) =0a(3) =4a(4) =4a(5) =16a(6) =12a(7) =32a(8) =20a(9) =112a(10) =88a(11) =384a(12) =308a(13) =1264a(14) =1056a(15) =4096a(16) =3852a(17) =15120a(18) =13820a(19) =52608a(20) =49824a(21) =190848a(22) =182356a(23) =704512a(24) =671540a(25) =2582128a(26) =2475220a(27) =9615744a(28) =9256428a(29) =35868672