74844

Appears in sequences

• Triangle read by rows: T(n,k) is number of noncrossing trees with n edges and having k nonroot branch nodes.at n=21A101431
• Expansion of b(q) / a(q) in powers of q of cubic AGM theta function.at n=6A115784
• Number of non-equivalent ways to choose two points in an equilateral triangle grid of side n.at n=42A227327
• Number T(n,k) of partitions of an n-set with distinct block sizes and maximal block size equal to k; triangle T(n,k), n>=0, ceiling((sqrt(1+8*n)-1)/2)<=k<=n, read by rows.at n=44A262072
• Number T(n,k) of partitions of an n-set with distinct block sizes and maximal block size equal to k; triangle T(n,k), k>=0, k<=n<=k*(k+1)/2, read by columns.at n=32A262078
• O.g.f. A(x) satisfies: [x^n] exp(-n^3*A(x)) / (1 - n*x)^(n^2) = 0, for n > 0.at n=5A320668
• Number of set partitions of [2n] with distinct block sizes and one of the block sizes is n.at n=6A328156
• Irregular triangle (an infinite binary tree) read by rows. The tree has root node 1 in row n = 1. For n > 1, each node with value m in row n-1 has a left child with value m / n if n divides m, and a right child with value m * n.at n=43A360298