Numbers m such that m^4-1 has no divisors d with 1 < d < m-1.

Terms

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