4787200

Appears in sequences

• A unitary phi reciprocal amicable number: consider two different numbers r, s which satisfy the following equation for some integer k: uphi(r) = uphi(s) = (1/k) * r * s / (r-s); or equivalently, 1/uphi(r) = 1/uphi(s) = k * (1/s - 1/r); sequence gives s numbers.at n=32A080767
• E.g.f. A(x) satisfies A(x) = x * exp(A(x)) * (1 - A(x)).at n=9A334316