A305540
Sequences linked to this entry ?
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A305540: Triangle read by rows: T(n,k) is the number of achiral loops (necklaces or bracelets) of length n using exactly k different colors.
identification, match triangle
1 · 1, 1 · 1, 2 · 1, 4, 3 … Σ 1, 2, 3, 8, 13, 44, 75, 308, …