219059

Properties

Appears in sequences

• a(n) is the least number such that d(a(n)) = d(R(a(n)))/n, where R(n) is the digit reverse of n and d(n) is the number of divisors of n.at n=31A284495
• Number of nX5 0..1 arrays with every element equal to 0, 1, 3, 4 or 7 king-move adjacent elements, with upper left element zero.at n=9A298498
• a(0) = 1; thereafter a(n) is the smallest prime divisor of the number C(6n+1) formeded from the concatenation of 1,2,3,...,6n+1.at n=55A320571
• Prime numbersat n=19534