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

Terms

a(0) =4a(1) =6a(2) =150a(3) =180a(4) =240a(5) =270a(6) =420a(7) =570a(8) =1290a(9) =1320a(10) =2310a(11) =2550a(12) =2730a(13) =3360a(14) =3390a(15) =4260a(16) =4650a(17) =5850a(18) =5880a(19) =6360a(20) =6780a(21) =9000a(22) =9240a(23) =9630a(24) =10530a(25) =10890a(26) =11970a(27) =13680a(28) =13830a(29) =14010