(n-1)-st elementary symmetric function of {1,3,7,15,31,63,...-1+2^n}.

A203011

(n-1)-st elementary symmetric function of {1,3,7,15,31,63,...-1+2^n}.

Terms

    a(0) =1a(1) =4a(2) =31a(3) =486a(4) =15381a(5) =978768a(6) =124918731a(7) =31932406170

External references