Numbers k such that (178*10^k - 7)/9 is prime.

Terms

a(0) =0a(1) =1a(2) =3a(3) =7a(4) =12a(5) =13a(6) =21a(7) =40a(8) =67a(9) =69a(10) =132a(11) =213a(12) =259a(13) =1056a(14) =1639a(15) =1653a(16) =2913a(17) =6183a(18) =7086a(19) =8466a(20) =27475a(21) =55390