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, 1), (-1, 0, 1), (1, 0, -1), (1, 1, 1)}.

A149272

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, 1), (-1, 0, 1), (1, 0, -1), (1, 1, 1)}.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =11a(4) =42a(5) =132a(6) =512a(7) =1737a(8) =6772a(9) =23922a(10) =93618a(11) =339030a(12) =1330402a(13) =4898974a(14) =19264646a(15) =71788549a(16) =282770996a(17) =1063149998a(18) =4193389956a(19) =15875202814a(20) =62687736884a(21) =238629003248a(22) =943200410068

External references