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)}.
A151278
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)}.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =10a(4) =26a(5) =66a(6) =178a(7) =488a(8) =1320a(9) =3674a(10) =10318a(11) =28728a(12) =81344a(13) =231634a(14) =655614a(15) =1876510a(16) =5391998a(17) =15423550a(18) =44473310a(19) =128605264a(20) =370583896a(21) =1074340126a(22) =3121406738a(23) =9043275450a(24) =26324579482a(25) =76763009234a(26) =223318464418a(27) =652169185724
External references
- oeis: A151278