Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, 0)}.
A151286
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, 0)}.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =20a(4) =70a(5) =260a(6) =986a(7) =3852a(8) =15284a(9) =61646a(10) =251636a(11) =1038026a(12) =4320900a(13) =18123780a(14) =76544604a(15) =325197844a(16) =1389044326a(17) =5961411840a(18) =25695687106a(19) =111190743966a(20) =482866090476
External references
- oeis: A151286