59071

Appears in sequences

• Triangle read by rows: T(n,k) is the number of ordered trees with n edges and having k branches of even length (n>=0, 0<=k<=floor(n/2)).at n=49A102004
• Number of paths in the first quadrant from (0,0) to (n,0) using steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0).at n=12A128720
• The maximal set of disjoint prime cycle permutations on n elements which generate unique subgroups of S(n).at n=9A186202
• Expansion of g.f. 1/((1 - x)^2*(1 - 3*x + 3*x^2)).at n=18A279231
• a(n) = a(n-1) + 3*a(n-2) + 9*a(n-3) with a(0)=0, a(1)=1, a(2)=4.at n=11A366314