Number of n-step one-sided prudent walks avoiding exactly three consecutive West steps.

Terms

a(0) =1a(1) =3a(2) =7a(3) =16a(4) =39a(5) =92a(6) =219a(7) =521a(8) =1238a(9) =2944a(10) =6999a(11) =16640a(12) =39562a(13) =94058a(14) =223623a(15) =531663a(16) =1264027a(17) =3005221a(18) =7144904a(19) =16986989a(20) =40386518a(21) =96018831a(22) =228284497a(23) =542745740a(24) =1290376448a(25) =3067866323a(26) =7293843428a(27) =17341091936a(28) =41228396592a(29) =98020395245