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, 1), (-1, 0, 1), (0, 1, -1), (1, -1, 1), (1, 1, 1)}.
A149721
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, 1), (-1, 0, 1), (0, 1, -1), (1, -1, 1), (1, 1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =17a(4) =73a(5) =301a(6) =1335a(7) =5875a(8) =26607a(9) =120881a(10) =557545a(11) =2580669a(12) =12048327a(13) =56455559a(14) =266063765a(15) =1257696177a(16) =5969105003a(17) =28403442281a(18) =135564388471a(19) =648421377681
External references
- oeis: A149721