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

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =32a(6) =57a(7) =64a(8) =65a(9) =85a(10) =87a(11) =128a(12) =256a(13) =512a(14) =1024a(15) =1245a(16) =1421a(17) =2048a(18) =3146a(19) =3330a(20) =3790a(21) =4096a(22) =6695a(23) =7257a(24) =8192a(25) =10137a(26) =16384a(27) =25884a(28) =32768a(29) =34420