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, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1)}.
A151463
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, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =44a(6) =150a(7) =508a(8) =1846a(9) =6764a(10) =25858a(11) =99709a(12) =395433a(13) =1582181a(14) =6453404a(15) =26545529a(16) =110719053a(17) =465350515a(18) =1976488255a(19) =8452069209a(20) =36442285744a(21) =158070027834a(22) =690215772176
External references
- oeis: A151463