A simple context-free grammar in a labeled universe: a(n) = A052743(n)-A052723(n), n>1.

A052724

A simple context-free grammar in a labeled universe: a(n) = A052743(n)-A052723(n), n>1.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =24a(5) =240a(6) =2160a(7) =30240a(8) =524160a(9) =9434880a(10) =188697600a(11) =4311014400a(12) =108254361600

External references