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

A151437

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

Terms

    a(0) =1a(1) =0a(2) =2a(3) =2a(4) =14a(5) =28a(6) =148a(7) =408a(8) =1948a(9) =6316a(10) =29164a(11) =103336a(12) =473860a(13) =1770364a(14) =8141872a(15) =31491484a(16) =145696432a(17) =577601620a(18) =2689508560a(19) =10864037780a(20) =50889023352a(21) =208655144644a(22) =982532205120

External references