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, 0), (0, 1), (1, 1)}.
A151282
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, 0), (0, 1), (1, 1)}.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =18a(4) =58a(5) =190a(6) =638a(7) =2170a(8) =7474a(9) =25974a(10) =90982a(11) =320738a(12) =1137002a(13) =4049838a(14) =14485326a(15) =52001290a(16) =187292514a(17) =676546790a(18) =2450311862a(19) =8895769714a(20) =32366225562a(21) =117995832990a(22) =430960312862
External references
- oeis: A151282