109549440

Appears in sequences

• a(n) is the smallest number x such that floor(sigma(sigma(x))/x) = n or the A098219(x) quotient equals n.at n=22A098221
• Number of ascending runs of length n in the permutations of [2n].at n=7A230382
• a(n) is the least integer k such that sigma(sigma(k)) >= n*k where sigma is A000203, the sum of divisors.at n=22A327630
• a(n) = (2n)!/(n!*a(n-2)), with a(0) = 1, a(1) = 1.at n=11A372988