2489344

Appears in sequences

• a(0) = 0; for n >= 1, a(n) = 2^(n-1)*C(n-1), where C(n) = A000108(n) Catalan numbers, n>0.at n=10A052701
• Number of unrooted Eulerian maps with bicolored faces which are self-isomorphic under reversing the colors.at n=18A090375
• Riordan array (1, x*c(2x)), c(x) the g.f. of A000108.at n=56A110510
• If X_1,...,X_n is a partition of a 2n-set X into 2-blocks then a(n) is equal to the number of 7-subsets of X containing none of X_i, (i=1,...n).at n=10A130813
• Number of walks within N^2 (the first quadrant of Z^2) starting at (0, 0), ending on the vertical axis and consisting of 2n steps taken from {(-1, -1), (-1, 0), (1, 1)}.at n=9A151374
• Number of 10-D hypercubes in an n-dimensional hypercube.at n=7A172242
• 10-quantum transitions in systems of N >= 10 spin 1/2 particles, in columns by combination indices.at n=16A213352
• Triangle read by rows: T(n,k) = number of colored weighted Motzkin paths ending at (n,k).at n=37A293172