Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of 4 n steps taken from {(-1, -1), (-1, 1), (1, 0)}.
A151332
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of 4 n steps taken from {(-1, -1), (-1, 1), (1, 0)}.
Terms
- a(0) =1a(1) =2a(2) =28a(3) =660a(4) =20020a(5) =705432a(6) =27457584a(7) =1147334760a(8) =50561468100
External references
- oeis: A151332