Numbers n such that sigma(n)=2n-2^d(n) where d(n) is number of positive divisors of n.

A110079

Numbers n such that sigma(n)=2n-2^d(n) where d(n) is number of positive divisors of n.

Terms

    a(0) =5a(1) =38a(2) =284a(3) =1370a(4) =2168a(5) =26828a(6) =133088a(7) =1515608a(8) =19414448a(9) =23521328a(10) =25812848a(11) =49353008a(12) =82988756a(13) =103575728a(14) =537394688a(15) =558504608a(16) =921747488a(17) =2651596448a(18) =17517611968a(19) =18249863488a(20) =77792665408a(21) =556915822208

External references