[ exp(7/23)*n! ].

Terms

a(0) =1a(1) =2a(2) =8a(3) =32a(4) =162a(5) =976a(6) =6832a(7) =54663a(8) =491971a(9) =4919711a(10) =54116823a(11) =649401885a(12) =8442224517a(13) =118191143240