A simple context-free grammar in a labeled universe: labeled version of A052703.

A052730

A simple context-free grammar in a labeled universe: labeled version of A052703.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =6a(4) =72a(5) =1440a(6) =35280a(7) =1058400a(8) =37376640a(9) =1520830080a(10) =70053984000

External references