Numbers k such that 421*2^k+1 is prime.

Terms

a(0) =4a(1) =8a(2) =12a(3) =16a(4) =24a(5) =36a(6) =72a(7) =196a(8) =576a(9) =928a(10) =3336a(11) =5172a(12) =5996a(13) =6196a(14) =13204a(15) =28484a(16) =36984a(17) =43740a(18) =58744a(19) =62244a(20) =112876a(21) =127852a(22) =143208a(23) =170612a(24) =174372a(25) =221372a(26) =350356a(27) =832528a(28) =1070460a(29) =1729092