Numbers k such that 47*2^k-1 is prime.

Terms

a(0) =4a(1) =14a(2) =70a(3) =78a(4) =1374a(5) =1824a(6) =2158a(7) =2654a(8) =4494a(9) =9598a(10) =10068a(11) =11524a(12) =15128a(13) =55408a(14) =87324a(15) =450470a(16) =540494a(17) =695384a(18) =695724