Numbers k such that k + sigma(k) is a triangular number.

Terms

a(0) =7a(1) =10a(2) =66a(3) =136a(4) =145a(5) =196a(6) =198a(7) =234a(8) =270a(9) =438a(10) =495a(11) =528a(12) =592a(13) =606a(14) =855a(15) =910a(16) =1045a(17) =1158a(18) =1428a(19) =2208a(20) =2718a(21) =2922a(22) =3016a(23) =3663a(24) =3808a(25) =3916a(26) =4506a(27) =4975a(28) =5043a(29) =5136