200160

Appears in sequences

• Triangle T(n,k), read by rows n>=0 with terms k=1..3^n, where row n lists the coefficients in the n-th iteration of (x+x^2+x^3).at n=50A166880
• The numbers k for which gcd(k, phi(k)) + gcd(k, tau(k)) = gcd(k, sigma(k)).at n=20A326416