Number of maximally-clustered hexagon-avoiding permutations in S_n; the maximally-clustered hexagon-avoiding permutations are those that avoid 3421, 4312, 4321, 46718235, 46781235, 56718234, 56781234.
A129776
Number of maximally-clustered hexagon-avoiding permutations in S_n; the maximally-clustered hexagon-avoiding permutations are those that avoid 3421, 4312, 4321, 46718235, 46781235, 56718234, 56781234.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =78a(6) =298a(7) =1157a(8) =4535a(9) =17872a(10) =70644a(11) =279704a(12) =1108462a(13) =4395045a(14) =17431206a(15) =69144643a(16) =274300461a(17) =1088215370a(18) =4317321235a(19) =17128527716a(20) =67956202025a(21) =269612504850
External references
- oeis: A129776