55150domain: NAppears in sequencesE.g.f.: Sum_{n>=0} (1 + exp(n*x))^n * x^n/n!.at n=6A326090Number of subsets of {1..n} where some element is a difference of two consecutive elements.at n=16A364466a(n) = Sum_{1 <= x_1, x_2 <= n} sigma( n/gcd(x_1, x_2, n) ).at n=31A373129