E.g.f. exp(sum_{d|M} (exp(d*x)-1)/d), M=15.

A141011

E.g.f. exp(sum_{d|M} (exp(d*x)-1)/d), M=15.

Terms

    a(0) =1a(1) =4a(2) =40a(3) =612a(4) =11976a(5) =276836a(6) =7336248a(7) =219610532a(8) =7331824360a(9) =269576919908

External references