Even composite integers m such that A004254(m)^2 == 1 (mod m).

Terms

a(0) =4a(1) =8a(2) =76a(3) =104a(4) =116a(5) =296a(6) =872a(7) =1112a(8) =1378a(9) =2204a(10) =2774a(11) =2834a(12) =3016a(13) =4472a(14) =5174a(15) =5624a(16) =6364a(17) =6554a(18) =8854a(19) =9164a(20) =9976a(21) =10564a(22) =11026a(23) =11324a(24) =11476a(25) =12644a(26) =14356a(27) =14456a(28) =15124a(29) =15544