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, 0), (0, 0, 1), (1, 1, -1)}.
A148320
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, 0), (0, 0, 1), (1, 1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =40a(6) =120a(7) =375a(8) =1212a(9) =3976a(10) =13262a(11) =44928a(12) =154484a(13) =536046a(14) =1876504a(15) =6623171a(16) =23568612a(17) =84362580a(18) =303647530a(19) =1098556826a(20) =3994948648a(21) =14586549832a(22) =53462105550a(23) =196642390104a(24) =725847534220
External references
- oeis: A148320