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), (1, 1, -1), (1, 1, 1)}.
A149428
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), (1, 1, -1), (1, 1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =13a(4) =44a(5) =156a(6) =560a(7) =2049a(8) =7684a(9) =28772a(10) =108368a(11) =412396a(12) =1573776a(13) =6029488a(14) =23226176a(15) =89573577a(16) =346281380a(17) =1343190436a(18) =5216949776a(19) =20296197484a(20) =79131832976a(21) =308798743728
External references
- oeis: A149428