Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (0, 1), (1, -1), (1, 0), (1, 1)}.
A151457
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (0, 1), (1, -1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =8a(4) =26a(5) =86a(6) =302a(7) =1091a(8) =4040a(9) =15271a(10) =58626a(11) =228160a(12) =897769a(13) =3566851a(14) =14287540a(15) =57643690a(16) =234033415a(17) =955486006a(18) =3920368468a(19) =16157046284a(20) =66855815475a(21) =277647691670
External references
- oeis: A151457