Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 3*b^2.

A216555

Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 3*b^2.

Terms

    a(0) =0a(1) =5a(2) =7a(3) =8a(4) =13a(5) =16a(6) =31a(7) =37a(8) =47a(9) =53a(10) =61a(11) =71a(12) =79a(13) =503a(14) =613a(15) =863a(16) =7741a(17) =19469a(18) =81671a(19) =94823a(20) =344293a(21) =532277a(22) =631181a(23) =637751a(24) =651821

External references