Terms of A222263 such that 2n/sigma(n) - 1 = 1/2^k, for some integer k.

A230166

Terms of A222263 such that 2n/sigma(n) - 1 = 1/2^k, for some integer k.

Terms

    a(0) =1a(1) =3a(2) =15a(3) =135a(4) =819a(5) =1365a(6) =1485a(7) =2295a(8) =9009a(9) =13923a(10) =63855a(11) =387387a(12) =397575a(13) =667275a(14) =14381055a(15) =16410735a(16) =99558459a(17) =271543725a(18) =3145425129a(19) =7096702977a(20) =741585912975

External references