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, 0, -1), (0, 1, 0), (1, 1, 1)}.
A150120
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, 0, -1), (0, 1, 0), (1, 1, 1)}.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =20a(4) =68a(5) =238a(6) =854a(7) =3106a(8) =11410a(9) =42306a(10) =158018a(11) =593584a(12) =2240768a(13) =8495266a(14) =32324970a(15) =123387316a(16) =472303236a(17) =1812388378a(18) =6970142194a(19) =26859338508a(20) =103688368988a(21) =400934226330
External references
- oeis: A150120