Composite integers k such that 2^k == 2 (mod k*(k+1)).

Terms

a(0) =561a(1) =1905a(2) =4033a(3) =4681a(4) =5461a(5) =6601a(6) =8481a(7) =11305a(8) =13741a(9) =13981a(10) =16705a(11) =23377a(12) =30121a(13) =31417a(14) =41041a(15) =49141a(16) =52633a(17) =57421a(18) =88357a(19) =88561a(20) =101101a(21) =107185a(22) =121465a(23) =130561a(24) =162193a(25) =196021a(26) =196093a(27) =204001a(28) =208465a(29) =219781