Number of walks of length n starting at origin and ending in first quadrant on a square lattice.

A187151

Number of walks of length n starting at origin and ending in first quadrant on a square lattice.

Terms

    a(0) =1a(1) =2a(2) =8a(3) =26a(4) =108a(5) =382a(6) =1586a(7) =5812a(8) =24044a(9) =89846a(10) =370398a(11) =1401292a(12) =5759826a(13) =21977516a(14) =90111820a(15) =345994216a(16) =1415691244a(17) =5461770406a(18) =22308412934a(19) =86392108636a(20) =352334866238

External references