E.g.f. exp(Sum_{d|M} (exp(d*x)-1)/d), M=13.

A141009

E.g.f. exp(Sum_{d|M} (exp(d*x)-1)/d), M=13.

Terms

    a(0) =1a(1) =2a(2) =18a(3) =262a(4) =4498a(5) =88174a(6) =1989162a(7) =51366438a(8) =1491069602a(9) =47749828830

External references