3571200

Appears in sequences

• Numbers k such that phi(sigma(k)) = k.at n=14A001229
• 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=19A030165
• Numbers k such that k = phi(sigma(phi(sigma(k)))).at n=30A067883
• Numbers k such that k = phi(sigma(phi(sigma(phi(sigma(k)))))).at n=29A067884
• Number of permutations of {1,...,n} avoiding adjacent step pattern up, down, up, up, up, up.at n=10A177547
• Number of permutations of {1,...,n} avoiding adjacent step pattern up, up, up, down, down, down.at n=10A177552
• Numbers which are the minimum of a cycle in the map x -> phi(sigma(x)).at n=32A376256