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

A151419

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

Terms

    a(0) =1a(1) =0a(2) =3a(3) =4a(4) =20a(5) =60a(6) =227a(7) =808a(8) =3146a(9) =11798a(10) =46638a(11) =182794a(12) =729704a(13) =2930082a(14) =11866477a(15) =48312364a(16) =198017220a(17) =815038874a(18) =3370875226a(19) =13995160516a(20) =58314718458a(21) =243770271046

External references