Odd numbers that do not divide 2^k + 1 for any k >= 1.

Terms

a(0) =7a(1) =15a(2) =21a(3) =23a(4) =31a(5) =35a(6) =39a(7) =45a(8) =47a(9) =49a(10) =51a(11) =55a(12) =63a(13) =69a(14) =71a(15) =73a(16) =75a(17) =77a(18) =79a(19) =85a(20) =87a(21) =89a(22) =91a(23) =93a(24) =95a(25) =103a(26) =105a(27) =111a(28) =115a(29) =117