Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 1), (-1, 0), (0, -1), (0, 1), (1, -1)}.
A151269
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 1), (-1, 0), (0, -1), (0, 1), (1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =7a(4) =25a(5) =74a(6) =281a(7) =958a(8) =3763a(9) =13945a(10) =56298a(11) =220242a(12) =909122a(13) =3693263a(14) =15531412a(15) =64853036a(16) =277086226a(17) =1181341989a(18) =5116502135a(19) =22172843919a(20) =97169314616a(21) =426672066925
External references
- oeis: A151269