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, 0), (0, 0, -1), (0, 1, 0), (1, 0, 1)}.
A149944
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, 0), (0, 0, -1), (0, 1, 0), (1, 0, 1)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =15a(4) =50a(5) =164a(6) =556a(7) =1940a(8) =6933a(9) =24744a(10) =89546a(11) =327038a(12) =1207300a(13) =4459302a(14) =16591211a(15) =61991530a(16) =233069224a(17) =876816387a(18) =3313333609a(19) =12551052159a(20) =47736490574a(21) =181653337777a(22) =693339189471
External references
- oeis: A149944