Numbers k such that k-1, k+1, and k^2-k-1 are primes.

Terms

a(0) =4a(1) =6a(2) =12a(3) =42a(4) =60a(5) =102a(6) =150a(7) =192a(8) =282a(9) =420a(10) =432a(11) =462a(12) =570a(13) =660a(14) =810a(15) =882a(16) =1062a(17) =1230a(18) =1320a(19) =1872a(20) =1950a(21) =2550a(22) =2712a(23) =2730a(24) =3120a(25) =3252a(26) =4020a(27) =4092a(28) =6090a(29) =8220