Array of (k^n + k^(-n))/2 where k = (sqrt(x^2-1) + x)^2 for integers x >= 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =7a(5) =1a(6) =1a(7) =97a(8) =17a(9) =1a(10) =1a(11) =1351a(12) =577a(13) =31a(14) =1a(15) =1a(16) =18817a(17) =19601a(18) =1921a(19) =49a(20) =1a(21) =1a(22) =262087a(23) =665857a(24) =119071a(25) =4801a(26) =71a(27) =1a(28) =1a(29) =3650401