Numbers k such that sigma(k*phi(k)) = sigma(k)^2.

Terms

a(0) =1a(1) =87a(2) =1257a(3) =42921a(4) =65307a(5) =68037a(6) =89067a(7) =112803a(8) =116619a(9) =186231a(10) =252417a(11) =350283a(12) =356259a(13) =380559a(14) =435993a(15) =477723a(16) =492771a(17) =527781a(18) =635259a(19) =672051a(20) =708111a(21) =866379a(22) =991479a(23) =1062723a(24) =1078509a(25) =1347699a(26) =1352199a(27) =1353873a(28) =1449363a(29) =1561431