Number of n-step one-sided prudent walks, avoiding exactly two consecutive west steps and two consecutive east steps.

A190570

Number of n-step one-sided prudent walks, avoiding exactly two consecutive west steps and two consecutive east steps.

Terms

    a(0) =1a(1) =3a(2) =5a(3) =13a(4) =27a(5) =63a(6) =137a(7) =309a(8) =683a(9) =1527a(10) =3393a(11) =7565a(12) =16835a(13) =37503a(14) =83497a(15) =185957a(16) =414075a(17) =922119a(18) =2053393a(19) =4572669a(20) =10182643a(21) =22675407a(22) =50494905a(23) =112445269a(24) =250399915a(25) =557606103a(26) =1241711393a(27) =2765119597a(28) =6157538211a(29) =13711985439

External references