Numbers k such that 55*10^k + 7 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =16a(5) =33a(6) =35a(7) =51a(8) =371a(9) =1539a(10) =1564a(11) =2897a(12) =3431a(13) =4448a(14) =6593a(15) =7066a(16) =7345a(17) =11770a(18) =20026a(19) =22114a(20) =23945a(21) =46946a(22) =60772