Nonprimes k > 0 such that 6^k==6 (mod k).

Terms

a(0) =1a(1) =6a(2) =10a(3) =15a(4) =21a(5) =30a(6) =35a(7) =105a(8) =185a(9) =190a(10) =217a(11) =231a(12) =301a(13) =430a(14) =435a(15) =481a(16) =561a(17) =777a(18) =1105a(19) =1111a(20) =1221a(21) =1261a(22) =1333a(23) =1729a(24) =1866a(25) =2121a(26) =2465a(27) =2553a(28) =2701a(29) =2821