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), (1, -1), (1, 1)}.
A151431
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), (1, -1), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =8a(4) =28a(5) =101a(6) =382a(7) =1494a(8) =6006a(9) =24743a(10) =103721a(11) =441326a(12) =1901396a(13) =8281588a(14) =36410636a(15) =161392093a(16) =720535739a(17) =3237425269a(18) =14629265198a(19) =66446525314a(20) =303203629717
External references
- oeis: A151431