Composite numbers k+1 such that k*phi(k+1) is a perfect square.

Terms

a(0) =9a(1) =27a(2) =50a(3) =169a(4) =242a(5) =245a(6) =945a(7) =1127a(8) =1280a(9) =1352a(10) =1694a(11) =2430a(12) =4335a(13) =4410a(14) =4624a(15) =4802a(16) =7500a(17) =7935a(18) =8624a(19) =11913a(20) =12544a(21) =13254a(22) =15050a(23) =16384a(24) =24642a(25) =27869a(26) =29403a(27) =31827a(28) =33489a(29) =36750