1304863560

Appears in sequences

• Smallest x such that sigma(x) = n*phi(x), or -1 if no such x exists.at n=26A055234
• a(n) = Min {x : sigma(x) = phi(n*x), x is not a prime}, least nonprime solutions to sigma(x) = phi(n*x).at n=26A087979
• a(n) = Min{x : sigma(x) = n*phi(x), x is not a prime}, the least nonprime solutions to sigma(x) = n*phi(x); special balanced numbers.at n=26A088830
• a(n) is the least number k > 0 such that sigma(k) = phi(n*k).at n=26A256527