2209584

Appears in sequences

• Numbers n for which phi(n) = phi(n-1) - phi(n+1).at n=15A220160
• Array read by downward antidiagonals: A(n,k) = (k+1)^2*A(n-1,k) + A(n-1,k+1) with A(0,k) = 1, n >= 0, k >= 0.at n=41A369527