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, 0, 0), (0, 1, 1), (1, -1, 1), (1, 1, -1)}.
A148968
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, 0, 0), (0, 1, 1), (1, -1, 1), (1, 1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =31a(5) =109a(6) =397a(7) =1469a(8) =5527a(9) =21011a(10) =80569a(11) =311003a(12) =1207035a(13) =4704737a(14) =18403149a(15) =72198531a(16) =283942611a(17) =1118999005a(18) =4417672911a(19) =17466703087a(20) =69149566107a(21) =274065214899
External references
- oeis: A148968