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, 0, -1), (0, 1, -1), (1, 0, 1)}.
A148573
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, 0, -1), (0, 1, -1), (1, 0, 1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =6a(4) =20a(5) =49a(6) =172a(7) =484a(8) =1732a(9) =5162a(10) =18965a(11) =59680a(12) =220777a(13) =715673a(14) =2685204a(15) =8953384a(16) =33734326a(17) =114539085a(18) =435187894a(19) =1503531596a(20) =5729591256a(21) =20035479823a(22) =76771639039a(23) =271669011838
External references
- oeis: A148573