The exponential transform of sigma(n).

Terms

a(0) =1a(1) =1a(2) =4a(3) =14a(4) =69a(5) =367a(6) =2284a(7) =15430a(8) =115146a(9) =924555a(10) =7991892a(11) =73547322a(12) =718621516a(13) =7410375897a(14) =80405501540a(15) =914492881330