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), (0, -1), (1, -1), (1, 0), (1, 1)}.

A151461

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), (0, -1), (1, -1), (1, 0), (1, 1)}.

Terms

    a(0) =1a(1) =0a(2) =2a(3) =3a(4) =13a(5) =34a(6) =133a(7) =433a(8) =1633a(9) =5906a(10) =22512a(11) =85330a(12) =331578a(13) =1293050a(14) =5109327a(15) =20311293a(16) =81413417a(17) =328184670a(18) =1330967868a(19) =5424040902a(20) =22208746242a(21) =91307247176a(22) =376832905242

External references