690563369

Appears in sequences

• Smallest k such that phi(phi(k)) = 2^n, where phi is the Euler totient function.at n=27A184968
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood.at n=31A279150