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, 0), (1, 0, 1), (1, 1, -1)}.
A149969
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, 0), (1, 0, 1), (1, 1, -1)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =16a(4) =55a(5) =195a(6) =719a(7) =2680a(8) =10130a(9) =38717a(10) =148870a(11) =576483a(12) =2242586a(13) =8757737a(14) =34320069a(15) =134835020a(16) =530974983a(17) =2094950165a(18) =8278736511a(19) =32762059345a(20) =129804162885a(21) =514821301922
External references
- oeis: A149969