Composite numbers k such that ((2^k+1)/3)^k == 1 (mod k^2).

Terms

a(0) =341a(1) =1105a(2) =1387a(3) =1729a(4) =1771a(5) =2047a(6) =2465a(7) =2485a(8) =2701a(9) =2821a(10) =3277a(11) =3445a(12) =4033a(13) =4369a(14) =4681a(15) =5185a(16) =5461a(17) =6601a(18) =7957a(19) =8321a(20) =8911a(21) =9361a(22) =10261a(23) =10585a(24) =11305a(25) =11713a(26) =11891a(27) =13741a(28) =13747a(29) =13981