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, 1), (1, 0, -1), (1, 1, 1)}.
A149273
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, 1), (1, 0, -1), (1, 1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =11a(4) =42a(5) =132a(6) =520a(7) =1761a(8) =6970a(9) =24604a(10) =97740a(11) =353886a(12) =1408456a(13) =5186830a(14) =20673334a(15) =77060191a(16) =307402490a(17) =1156225566a(18) =4615394884a(19) =17481280422a(20) =69812708258a(21) =265891539128
External references
- oeis: A149273