Number of length n inversion sequences avoiding the patterns 110, 120, 201, and 210.

A279568

Number of length n inversion sequences avoiding the patterns 110, 120, 201, and 210.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =22a(5) =90a(6) =396a(7) =1833a(8) =8801a(9) =43441a(10) =219092a(11) =1124201a(12) =5850414a(13) =30805498a(14) =163824559a(15) =878655117a(16) =4747341879a(17) =25815026491a(18) =141173582016a(19) =775920816789

External references