520025

Appears in sequences

• Expansion of (1-x)/(1 - x - x^2 - 3*x^3 + 3*x^4).at n=22A052915
• Numbers k such that phi(k)/lambda(k) increases to a record value, where phi(k) is the Euler totient function (A000010) and lambda(k) is the Carmichael lambda function (A002322).at n=31A066605
• Final terms of rows of A077529.at n=24A077530