Number of length n inversion sequences avoiding the patterns 110, 120, and 021.

A279557

Number of length n inversion sequences avoiding the patterns 110, 120, and 021.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =20a(5) =68a(6) =233a(7) =805a(8) =2807a(9) =9879a(10) =35073a(11) =125513a(12) =452389a(13) =1641029a(14) =5986994a(15) =21954974a(16) =80884424a(17) =299233544a(18) =1111219334a(19) =4140813374a(20) =15478839554a(21) =58028869154a(22) =218123355524a(23) =821908275548

External references