30108672

Appears in sequences

• Numbers m such that uphi(sigma(m)) = 2m, where the unitary phi function (A047994) is defined by: if x = p1^r1*p2^r2*p3^r3*... then uphi(x) = (p1^r1 - 1)*(p2^r2 - 1)*(p3^r3 - 1)*...at n=28A030165
• a(n) = 121*12^(n-2), a(0)=1, a(1)=10.at n=7A056116