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, -1), (-1, 0), (0, -1), (0, 1), (1, 0)}.
A151364
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, -1), (-1, 0), (0, -1), (0, 1), (1, 0)}.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =2a(4) =10a(5) =26a(6) =86a(7) =312a(8) =1022a(9) =3978a(10) =14098a(11) =55214a(12) =209256a(13) =825384a(14) =3259848a(15) =13047190a(16) =52796942a(17) =214867958a(18) =883609140a(19) =3650644490a(20) =15200444924a(21) =63591578852a(22) =267560620976
External references
- oeis: A151364