Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0)}.
A151366
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0)}.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =2a(4) =12a(5) =30a(6) =130a(7) =462a(8) =1946a(9) =7980a(10) =34776a(11) =153120a(12) =694056a(13) =3194334a(14) =14971242a(15) =71133062a(16) =342500730a(17) =1667918824a(18) =8208038124a(19) =40772105244a(20) =204270936480
External references
- oeis: A151366