Number of modified ascent sequences of length n avoiding the pattern 221.
A368636
Number of modified ascent sequences of length n avoiding the pattern 221.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =44a(6) =155a(7) =607a(8) =2617a(9) =12306a(10) =62587a(11) =341790a(12) =1991916a(13) =12324031a(14) =80587935a(15) =554826429a(16) =4008364544a(17) =30299290911a(18) =239019427636
External references
- oeis: A368636