Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 1), (-1, 0), (0, 1), (1, -1)}.
A151260
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 1), (-1, 0), (0, 1), (1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =40a(6) =129a(7) =410a(8) =1357a(9) =4554a(10) =15889a(11) =55393a(12) =198101a(13) =714134a(14) =2608715a(15) =9604663a(16) =35746763a(17) =133855284a(18) =505329127a(19) =1918867073a(20) =7331462511a(21) =28154364640a(22) =108675692369a(23) =421316437364
External references
- oeis: A151260