Numbers k such that (25*10^k - 13)/3 is prime.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =8a(5) =18a(6) =21a(7) =33a(8) =56a(9) =301a(10) =381a(11) =426a(12) =769a(13) =1123a(14) =1638a(15) =2037a(16) =2660a(17) =3284a(18) =4723a(19) =5686a(20) =17227a(21) =22084a(22) =25009a(23) =36176a(24) =125076a(25) =141019