Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, 0), (0, 1), (1, -1), (1, 1)}.
A151293
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, 0), (0, 1), (1, -1), (1, 1)}.
Terms
- a(0) =1a(1) =2a(2) =7a(3) =24a(4) =88a(5) =328a(6) =1246a(7) =4779a(8) =18485a(9) =71918a(10) =281102a(11) =1102653a(12) =4337842a(13) =17104951a(14) =67577658a(15) =267410057a(16) =1059581561a(17) =4203221319a(18) =16689714274a(19) =66324649355a(20) =263761185264
External references
- oeis: A151293