Numbers n such that (n(n+1)/2) modulo sigma(n) = n.

Terms

a(0) =33a(1) =136a(2) =145a(3) =261a(4) =897a(5) =1441a(6) =2016a(7) =2241a(8) =2353a(9) =3808a(10) =4320a(11) =7201a(12) =17101a(13) =26937a(14) =30721a(15) =32896a(16) =46593a(17) =70561a(18) =148960a(19) =151633a(20) =169345a(21) =174592a(22) =208801a(23) =400401a(24) =578593a(25) =712801a(26) =803800a(27) =1040401a(28) =1103233a(29) =1596673