Numbers k such that sigma(k) + phi(k) is a perfect square.

Terms

a(0) =2a(1) =4a(2) =56a(3) =110a(4) =125a(5) =161a(6) =287a(7) =391a(8) =418a(9) =423a(10) =511a(11) =588a(12) =609a(13) =675a(14) =721a(15) =799a(16) =910a(17) =935a(18) =1048a(19) =1057a(20) =1102a(21) =1130a(22) =1281a(23) =1351a(24) =1457a(25) =1485a(26) =1630a(27) =1716a(28) =1799a(29) =1826