9265217536

Appears in sequences

• Least x=a(n) such that product of common prime-divisors [without multiplicity] of sigma(x) and phi(x) equals n; or 0 if n is not a squarefree number or if no such x exists. Among indices n only squarefree numbers arise because multiplicity of prime factors is ignored.at n=46A082057
• (1,1) entry of powers of the orthogonal design shown below.at n=22A087621