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), (-1, 1, 0), (0, 0, -1), (0, 0, 1), (1, 0, 0)}.

A150055

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), (-1, 1, 0), (0, 0, -1), (0, 0, 1), (1, 0, 0)}.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =18a(4) =62a(5) =217a(6) =818a(7) =3121a(8) =12381a(9) =49571a(10) =203049a(11) =839400a(12) =3521390a(13) =14897035a(14) =63638310a(15) =273791526a(16) =1186143557a(17) =5169379953a(18) =22649963428a(19) =99731867420a(20) =441044844823

External references