a(1) = 1; for n > 1, a(n) is the smallest number m such that sigma(m) = tau(m)^n or 0 if no such m exists.

A349006

a(1) = 1; for n > 1, a(n) is the smallest number m such that sigma(m) = tau(m)^n or 0 if no such m exists.

Terms

    a(0) =1a(1) =3a(2) =7a(3) =217a(4) =31a(5) =3937a(6) =127a(7) =57337a(8) =253921a(9) =917497a(10) =3670009a(11) =16252897a(12) =8191a(14) =1073602561a(15) =4294434817a(16) =131071a(17) =66571993057a(18) =524287

External references