Prime powers k such that lcm(1, 2, 3, ..., k)-1 is prime.

Terms

a(0) =3a(1) =4a(2) =5a(3) =7a(4) =8a(5) =19a(6) =23a(7) =29a(8) =32a(9) =47a(10) =61a(11) =97a(12) =181a(13) =233a(14) =307a(15) =401a(16) =887a(17) =1021a(18) =1087a(19) =1361a(20) =1481a(21) =2053a(22) =2293a(23) =5407a(24) =5857a(25) =11059a(26) =14281a(27) =27277a(28) =27803a(29) =36497