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, -1), (-1, 0), (0, -1), (0, 1), (1, 0)}.

A151426

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, -1), (-1, 0), (0, -1), (0, 1), (1, 0)}.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =8a(4) =25a(5) =85a(6) =291a(7) =1072a(8) =3949a(9) =15143a(10) =58563a(11) =231111a(12) =922494a(13) =3724920a(14) =15196256a(15) =62498021a(16) =259151683a(17) =1081560013a(18) =4542825176a(19) =19184568461a(20) =81432735810a(21) =347241072470

External references