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), (0, 1, 1), (1, 0, 0)}.
A149945
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), (0, 1, 1), (1, 0, 0)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =15a(4) =50a(5) =164a(6) =572a(7) =2007a(8) =7147a(9) =25744a(10) =94470a(11) =345562a(12) =1283521a(13) =4774425a(14) =17870925a(15) =67071406a(16) =253596740a(17) =957841394a(18) =3641689270a(19) =13852713872a(20) =52882413683a(21) =202064486221a(22) =775138650253
External references
- oeis: A149945