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, -1), (0, 1, 0), (1, 0, 0)}.
A149820
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, -1), (0, 1, 0), (1, 0, 0)}.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =10a(4) =28a(5) =80a(6) =247a(7) =793a(8) =2558a(9) =8550a(10) =29174a(11) =99856a(12) =348717a(13) =1233071a(14) =4370391a(15) =15686057a(16) =56763062a(17) =205799392a(18) =752476359a(19) =2767134060a(20) =10192178158a(21) =37765951585a(22) =140525915462a(23) =523621511694
External references
- oeis: A149820