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), (0, -1), (1, -1), (1, 0), (1, 1)}.
A151456
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), (0, -1), (1, -1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =2a(4) =10a(5) =21a(6) =81a(7) =224a(8) =803a(9) =2561a(10) =9050a(11) =30870a(12) =110319a(13) =390692a(14) =1416287a(15) =5140142a(16) =18897316a(17) =69766341a(18) =259721708a(19) =971424259a(20) =3655211118a(21) =13814548450a(22) =52455943266a(23) =199966174108a(24) =765230937806
External references
- oeis: A151456