a(n) = A000108(n)*A002605(n+1), where A000108 are the Catalan numbers.

A185020

a(n) = A000108(n)*A002605(n+1), where A000108 are the Catalan numbers.

Terms

    a(0) =1a(1) =2a(2) =12a(3) =80a(4) =616a(5) =5040a(6) =43296a(7) =384384a(8) =3500640a(9) =32517056a(10) =306896512a(11) =2934597120a(12) =28369508608a(13) =276810483200

External references