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), (0, 1), (1, 0), (1, 1)}.
A151315
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), (0, 1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =3a(2) =10a(3) =37a(4) =138a(5) =526a(6) =2030a(7) =7877a(8) =30782a(9) =120726a(10) =475008a(11) =1874068a(12) =7407446a(13) =29329716a(14) =116285466a(15) =461555291a(16) =1833766116a(17) =7291280658a(18) =29011041208a(19) =115498923044a(20) =460056287616
External references
- oeis: A151315