Number of distinct solutions of sum{i=1..4}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1.

Terms

a(0) =0a(1) =0a(2) =7a(3) =30a(4) =142a(5) =502a(6) =1519a(7) =3828a(8) =9145a(9) =18966a(10) =38562a(11) =70202a(12) =127954a(13) =211261a(14) =357465a(15) =549988a(16) =875942a(17) =1273587a(18) =1941522a(19) =2705012a(20) =3966472a(21) =5325916a(22) =7599591a(23) =9892052a(24) =13772034a(25) =17476435a(26) =23770735a(27) =29625591a(28) =39617904a(29) =48129046