Numbers k such that k^2 +- k +- 1 is prime for all four possibilities.

Terms

a(0) =3a(1) =6a(2) =21a(3) =456a(4) =1365a(5) =2205a(6) =2451a(7) =2730a(8) =8541a(9) =18486a(10) =32199a(11) =32319a(12) =32781a(13) =45864a(14) =61215a(15) =72555a(16) =72561a(17) =82146a(18) =83259a(19) =86604a(20) =91371a(21) =95199a(22) =125334a(23) =149331a(24) =176889a(25) =182910a(26) =185535a(27) =210846a(28) =225666a(29) =226254