295569

Appears in sequences

• Nonsquarefree "year numbers" (numbers n such that phi(n) = 2*phi(sigma(n)): A137815).at n=11A137816
• Cubeful "year numbers" (such that phi(n) = 2 phi(sigma(n)): A137815).at n=0A137817
• Non-biquadratefree "year numbers": phi(n) = 2 phi(sigma(n)) and p^4 | n for some p>1.at n=0A137818