Number of self-avoiding planar walks of length n+1 starting at (0,0), ending at (n,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restriction that (0,1) is never used below the diagonal and (1,0) is never used above the diagonal.

A284778

Number of self-avoiding planar walks of length n+1 starting at (0,0), ending at (n,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restriction that (0,1) is never used below the diagonal and (1,0) is never used above the diagonal.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =4a(4) =8a(5) =22a(6) =54a(7) =142a(8) =370a(9) =983a(10) =2627a(11) =7086a(12) =19238a(13) =52561a(14) =144377a(15) =398518a(16) =1104794a(17) =3074809a(18) =8588093a(19) =24064642a(20) =67630898a(21) =190584766a(22) =538412426a(23) =1524554956a(24) =4326119748a(25) =12300296227a(26) =35037658099a(27) =99977847308a(28) =285741659312a(29) =817901027070

External references