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), (1, -1, 0), (1, 0, -1), (1, 1, 1)}.
A149427
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), (1, -1, 0), (1, 0, -1), (1, 1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =13a(4) =44a(5) =150a(6) =548a(7) =1979a(8) =7324a(9) =27074a(10) =101620a(11) =381338a(12) =1444860a(13) =5478476a(14) =20902380a(15) =79824913a(16) =306175148a(17) =1175699494a(18) =4528970884a(19) =17465198198a(20) =67512268620a(21) =261240684772
External references
- oeis: A149427