Numbers k such that sigma(k) = sigma(sigma(k)-k).

Terms

a(0) =6a(1) =28a(2) =220a(3) =284a(4) =496a(5) =1184a(6) =1210a(7) =2620a(8) =2924a(9) =5020a(10) =5564a(11) =6232a(12) =6368a(13) =8128a(14) =10744a(15) =10856a(16) =12285a(17) =14595a(18) =17296a(19) =18416a(20) =63020a(21) =66928a(22) =66992a(23) =67095a(24) =69615a(25) =71145a(26) =76084a(27) =79750a(28) =87633a(29) =88730