A120986
Sequences linked to this entry ?
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A120986: Triangle read by rows: T(n,k) is the number of ternary trees with n edges and having k middle edges (n >= 0, k >= 0).
identification, match triangle
1 · 2, 1 · 5, 6, 1 · 14, 28, 12, 1 … Σ 1, 3, 12, 55, 273, 1428, 7752, 43263, …