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)}.

A151428

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) =0a(2) =2a(3) =2a(4) =10a(5) =22a(6) =90a(7) =236a(8) =970a(9) =2952a(10) =11436a(11) =39148a(12) =148540a(13) =536112a(14) =2051152a(15) =7635144a(16) =29434148a(17) =112247828a(18) =436062188a(19) =1690577540a(20) =6627115320a(21) =25997584500a(22) =102759869944a(23) =406976897928

External references