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), (1, 1)}.

A151493

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), (1, 1)}.

Terms

    a(0) =1a(1) =1a(2) =6a(3) =20a(4) =114a(5) =529a(6) =3050a(7) =16333a(8) =96291a(9) =554489a(10) =3343913a(11) =20074658a(12) =123474818a(13) =761154695a(14) =4758617798a(15) =29876386844a(16) =189275072084

External references