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, 1), (1, 0, 1), (1, 1, -1)}.
A150129
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, 1), (1, 0, 1), (1, 1, -1)}.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =20a(4) =72a(5) =262a(6) =986a(7) =3732a(8) =14308a(9) =55280a(10) =214610a(11) =837858a(12) =3281386a(13) =12889822a(14) =50761728a(15) =200279230a(16) =791619506a(17) =3133268528a(18) =12416918448a(19) =49259337824a(20) =195589455772a(21) =777223955192
External references
- oeis: A150129