Smallest composite x such that sigma(x+2^n) = sigma(x) + 2^n.

Terms

a(0) =434a(1) =305635357a(2) =27a(3) =39a(4) =106645a(5) =69a(6) =2275a(7) =63a(8) =6475a(9) =249a(10) =7735a(11) =3703a(12) =10803a(13) =16383a(14) =58869a(15) =51181a(16) =87951a(17) =1695a(18) =9579a(19) =105237a(20) =98829a(21) =1143369a(22) =789609a(23) =11625a(24) =14038691a(25) =178975a(26) =48627929a(27) =1881333a(28) =402373721a(29) =2667945