61959domain: NAppears in sequencesa(n) = (1/n!)*A001689(n).at n=7A094794a(n) = (n+6)*a(n-1) + (n-1)*a(n-2), a(-1)=0, a(0)=1.at n=5A176733Expansion of e.g.f. f(x) * exp(2 * f(x)), where f(x) = (exp(3*x) - 1)/3.at n=6A383261