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

A151446

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

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =13a(5) =39a(6) =120a(7) =393a(8) =1327a(9) =4621a(10) =16507a(11) =60136a(12) =223256a(13) =841162a(14) =3213799a(15) =12423749a(16) =48544749a(17) =191494444a(18) =761889311a(19) =3054986938a(20) =12336481332a(21) =50140341202a(22) =205001854887a(23) =842763707626

External references