Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, 1), (1, -1), (1, 0)}.
A151357
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, 1), (1, -1), (1, 0)}.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =3a(4) =4a(5) =20a(6) =65a(7) =175a(8) =742a(9) =2604a(10) =9072a(11) =36960a(12) =139392a(13) =538824a(14) =2198625a(15) =8735727a(16) =35456850a(17) =146812952a(18) =604215326a(19) =2521642266a(20) =10617725768a(21) =44760668160a(22) =190357768328a(23) =813800295880
External references
- oeis: A151357