Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (-1, 1), (0, -1), (0, 1), (1, 0)}.
A151447
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (-1, 1), (0, -1), (0, 1), (1, 0)}.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =10a(4) =39a(5) =130a(6) =514a(7) =1943a(8) =7872a(9) =31706a(10) =131650a(11) =549751a(12) =2331370a(13) =9963328a(14) =42980063a(15) =186704975a(16) =816434120a(17) =3590695220a(18) =15873104022a(19) =70496228150a(20) =314392868577
External references
- oeis: A151447