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), (0, 1, -1), (0, 1, 1), (1, 0, 0)}.
A149947
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), (0, 1, -1), (0, 1, 1), (1, 0, 0)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =15a(4) =50a(5) =169a(6) =598a(7) =2164a(8) =7854a(9) =29048a(10) =108552a(11) =406591a(12) =1537770a(13) =5850165a(14) =22293452a(15) =85434661a(16) =328608808a(17) =1265532082a(18) =4891237026a(19) =18950820179a(20) =73496281444a(21) =285726717792
External references
- oeis: A149947