From a problem concerning circulant matrices and Gauss sums.

Terms

a(0) =1a(1) =8a(2) =81a(3) =640a(4) =821a(5) =648a(6) =9031a(7) =14336a(8) =32805a(9) =6568a(10) =17051a(11) =51840a(12) =122461a(13) =72248a(14) =66501a(15) =360448a(16) =92753a(17) =262440a(18) =586531