a(n) is the number of diagonalizable 2 X 2 matrices over GF(prime(n)).

Terms

a(0) =8a(1) =39a(2) =305a(3) =1183a(4) =7271a(5) =14209a(6) =41633a(7) =64999a(8) =139679a(9) =353249a(10) =461311a(11) =936433a(12) =1412081a(13) =1708519a(14) =2438783a(15) =3943889a(16) =6056999a(17) =6921121a(18) =10073383a(19) =12703391a(20) =14196529a(21) =19471999a(22) =23725799a(23) =31367249a(24) =44260033a(25) =52025201a(26) =56270239a(27) =65534183a(28) =70573249a(29) =81517409