Number of valid hook configurations of permutations of [n] that avoid the patterns 231 and 1243.
A307789
Number of valid hook configurations of permutations of [n] that avoid the patterns 231 and 1243.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =13a(6) =35a(7) =96a(8) =267a(9) =750a(10) =2123a(11) =6046a(12) =17303a(13) =49721a(14) =143365a(15) =414584a(16) =1201917a(17) =3492117a(18) =10165779a(19) =29643870a(20) =86574831a(21) =253188111a(22) =741365049a(23) =2173243128a(24) =6377181825a(25) =18730782252a(26) =55062586341a(27) =161995031226a(28) =476941691177
External references
- oeis: A307789