421192

Appears in sequences

• Numbers n such that phi(n)=phi(d_1)^phi(d_1)*phi(d_2)^phi(d_2)* ...*phi(d_k)^phi(d_k) where d_1 d_2 ... d_k is the decimal expansion of n.at n=5A104898
• Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum not 1 3 6 or 8 and every diagonal and antidiagonal sum 1 3 6 or 8.at n=10A252048
• Sum of all squarefree semiprimes with greater prime factor prime(n).at n=37A339194