Nonprime solutions to k == -1 (mod phi(k+1)).

Terms

a(0) =1a(1) =15a(2) =35a(3) =63a(4) =95a(5) =143a(6) =161a(7) =215a(8) =255a(9) =287a(10) =323a(11) =485a(12) =511a(13) =575a(14) =767a(15) =1023a(16) =1295a(17) =1457a(18) =1535a(19) =1727a(20) =1943a(21) =2047a(22) =2303a(23) =2915a(24) =3071a(25) =3455a(26) =3887a(27) =4095a(28) =4607a(29) =5183