2337513

Appears in sequences

• Numbers n that enter a cycle of greater length than that for any k < n in the iteration sequence s(0)=n, s(k+1) = s(k) + (-1)^k*d(s(k)), where d(n) is the number of divisors of n (A000005).at n=9A285004
• a(n) is the least number that enters a cycle of length 2n in the iteration sequence s(0)=n, s(k+1) = s(k) + (-1)^k*d(s(k)), where d(n) is the number of divisors of n (A000005).at n=12A288070
• a(n) = n! * Sum_{k=1..n} 1/(k! * floor(n/k)!).at n=10A355991