Numbers k such that 4*10^k + 91 is prime.

Terms

a(0) =1a(1) =2a(2) =3a(3) =8a(4) =10a(5) =15a(6) =31a(7) =32a(8) =77a(9) =106a(10) =191a(11) =197a(12) =525a(13) =557a(14) =1958a(15) =3848a(16) =12771a(17) =13348a(18) =13507a(19) =23164a(20) =55932a(21) =67375a(22) =68020a(23) =95407a(24) =95672a(25) =109142a(26) =113905a(27) =150577a(28) =185905a(29) =261248