Odd squarefree numbers k for which m >= 0 can be found such that k*2^m divides sigma(k*2^m).

A320026

Odd squarefree numbers k for which m >= 0 can be found such that k*2^m divides sigma(k*2^m).

Terms

    a(0) =1a(1) =3a(2) =7a(3) =15a(4) =21a(5) =31a(6) =127a(7) =1023a(8) =8191a(9) =131071a(10) =180213a(11) =524287a(12) =1796165a(13) =3112865a(14) =5388495a(15) =9338595a(16) =2147483647

External references