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, 1), (0, -1, 1), (0, 1, -1), (1, 1, 0)}.
A148931
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, 1), (0, -1, 1), (0, 1, -1), (1, 1, 0)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =28a(5) =96a(6) =331a(7) =1178a(8) =4277a(9) =15668a(10) =58207a(11) =217827a(12) =820822a(13) =3113057a(14) =11858060a(15) =45369618a(16) =174201971a(17) =670880989a(18) =2590897603a(19) =10028967336a(20) =38902441680a(21) =151185031351a(22) =588509650239
External references
- oeis: A148931