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), (-1, 1), (0, -1), (1, -1), (1, 1)}.
A151356
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), (-1, 1), (0, -1), (1, -1), (1, 1)}.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =2a(4) =8a(5) =22a(6) =101a(7) =364a(8) =1618a(9) =6702a(10) =30512a(11) =135904a(12) =634610a(13) =2958340a(14) =14147829a(15) =67996988a(16) =331941976a(17) =1631261090a(18) =8101797506a(19) =40502662220a(20) =204075069854
External references
- oeis: A151356