Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (0, 1, 0), (1, 0, 1), (1, 1, -1)}.
A149960
Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (0, 1, 0), (1, 0, 1), (1, 1, -1)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =16a(4) =54a(5) =186a(6) =663a(7) =2388a(8) =8749a(9) =32509a(10) =121494a(11) =457682a(12) =1733295a(13) =6595168a(14) =25218573a(15) =96727444a(16) =372169841a(17) =1435821588a(18) =5551953314a(19) =21517134765a(20) =83539873826a(21) =324881623016
External references
- oeis: A149960