Numbers k such that k - 2 | sigma(k).

Terms

a(0) =1a(1) =3a(2) =5a(3) =6a(4) =14a(5) =44a(6) =110a(7) =152a(8) =884a(9) =2144a(10) =8384a(11) =18632a(12) =116624a(13) =8394752a(14) =15370304a(15) =73995392a(16) =536920064a(17) =2147581952a(18) =34360131584