A simple context-free grammar in a labeled universe: labeled version of A052708.
A052738
A simple context-free grammar in a labeled universe: labeled version of A052708.
Terms
- a(0) =0a(1) =0a(2) =2a(3) =12a(4) =120a(5) =1920a(6) =40320a(7) =1028160a(8) =30965760a(9) =1077753600a(10) =42551308800
External references
- oeis: A052738