Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of 2 n steps taken from {(-1, -1), (-1, 1), (1, -1), (1, 0)}.
A151500
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of 2 n steps taken from {(-1, -1), (-1, 1), (1, -1), (1, 0)}.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =28a(4) =202a(5) =1634a(6) =14356a(7) =134442a(8) =1320582a(9) =13475838a(10) =141858494a(11) =1532365936a(12) =16917613816a(13) =190293921824
External references
- oeis: A151500