648675

Appears in sequences

• Let f(i) = prime( f(i - 1) (modulo 10^n) ) with f(0) = 1; a(n) is the length of the period of the sequence f(i).at n=12A128867
• Number of chordless cycles in the complete tripartite graph K_{n,n,n}.at n=30A297662
• Odd numbers k such that rad(k) divides sigma(k).at n=35A336554
• Powerful numbers (A001694) whose sum of powerful divisors (including 1) is also powerful.at n=16A349109