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

Terms

a(0) =188a(1) =1155a(2) =2540a(3) =5831a(4) =6560a(5) =8449a(6) =9074a(7) =11235a(8) =11448a(9) =25885a(10) =32318a(11) =54144a(12) =56168a(13) =61016a(14) =63535a(15) =76879a(16) =91874a(17) =99980a(18) =118335a(19) =119144a(20) =123100a(21) =127007a(22) =146015a(23) =153759a(24) =219699a(25) =227528a(26) =234255a(27) =243048a(28) =280370a(29) =404319