Number of rules of a context-free grammar in Chomsky normal form that generates all permutations of n symbols.
A090326
Number of rules of a context-free grammar in Chomsky normal form that generates all permutations of n symbols.
Terms
- a(0) =1a(1) =4a(2) =15a(3) =54a(4) =185a(5) =608a(6) =1939a(7) =6058a(8) =18669a(9) =57012a(10) =173063a(11) =523262a(12) =1577953a(13) =4750216a(14) =14283387a(15) =42915666a(16) =128878037a(17) =386896220a(18) =1161212911a(19) =3484687270a(20) =10456158921a(21) =31372671024a(22) =94126401635a(23) =282395982074a(24) =847221500605
External references
- oeis: A090326