Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, 0), (1, 1)}.
A151474
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =16a(4) =72a(5) =310a(6) =1458a(7) =6954a(8) =34290a(9) =171942a(10) =877782a(11) =4539912a(12) =23760136a(13) =125569340a(14) =669355076a(15) =3594689358a(16) =19432582910a(17) =105666075398a(18) =577578487822
External references
- oeis: A151474