a(n) = n! * [x^n] exp(n*x)/(1 + LambertW(-x)).

A290840

a(n) = n! * [x^n] exp(n*x)/(1 + LambertW(-x)).

Terms

    a(0) =1a(1) =2a(2) =12a(3) =117a(4) =1584a(5) =27525a(6) =585108a(7) =14726411a(8) =428551616a(9) =14161828185a(10) =523952280900

External references