Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, 1)}.
A151367
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, 1)}.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =2a(4) =13a(5) =27a(6) =140a(7) =392a(8) =1882a(9) =6289a(10) =28906a(11) =107949a(12) =486438a(13) =1948638a(14) =8730438a(15) =36611160a(16) =164259758a(17) =710530289a(18) =3203433595a(19) =14163150429a(20) =64260242637a(21) =288694503092
External references
- oeis: A151367