Numbers k such that sigma(k) = sigma(k-1).

Terms

a(0) =15a(1) =207a(2) =958a(3) =1335a(4) =1365a(5) =1635a(6) =2686a(7) =2975a(8) =4365a(9) =14842a(10) =18874a(11) =19359a(12) =20146a(13) =24958a(14) =33999a(15) =36567a(16) =42819a(17) =56565a(18) =64666a(19) =74919a(20) =79827a(21) =79834a(22) =84135a(23) =92686a(24) =109215a(25) =111507a(26) =116938a(27) =122074a(28) =138238a(29) =147455