Numbers k such that k divides 2^(2*k+1) - 1.

Terms

a(0) =1a(1) =7a(2) =217a(3) =1057a(4) =3937a(5) =10447a(6) =24601a(7) =32767a(8) =91657a(9) =145337a(10) =279527a(11) =666967a(12) =1412113a(13) =2484247a(14) =2874847a(15) =3124327a(16) =4169137a(17) =4472167a(18) =9526207a(19) =12021439a(20) =16539337a(21) =16646017a(22) =19384207a(23) =20139367a(24) =24639727a(25) =28127137a(26) =28940887a(27) =30583087a(28) =66131279a(29) =68068777