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

A151508

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

Terms

    a(0) =1a(1) =0a(2) =2a(3) =1a(4) =12a(5) =13a(6) =106a(7) =184a(8) =1167a(9) =2749a(10) =14976a(11) =43184a(12) =214494a(13) =709375a(14) =3334182a(15) =12111401a(16) =55172493a(17) =213825895a(18) =958512287a(19) =3886970215a(20) =17308095926a(21) =72488219249a(22) =322457272822

External references