Numbers k for which 6*k+1 divides 2^k-1.

Terms

a(0) =5a(1) =21a(2) =37a(3) =72a(4) =73a(5) =76a(6) =100a(7) =121a(8) =153a(9) =221a(10) =233a(11) =237a(12) =245a(13) =276a(14) =288a(15) =292a(16) =296a(17) =300a(18) =305a(19) =333a(20) =336a(21) =341a(22) =348a(23) =352a(24) =357a(25) =380a(26) =381a(27) =397a(28) =445a(29) =448