17611882496
domain: N
Appears in sequences
- Apart from the leading term, a(n) = Catalan(n-1)*4^(n-1).at n=11A052704
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of 2*n steps taken from {(-1, 0), (-1, 1), (1, 0), (1, 1)}.at n=10A151403
- a(n) = 2^n*n!/((floor(n/2)+1)*floor(n/2)!^2).at n=20A240558