A334218
identification: the entry's rule defines the sequence for every index; tail: the sequence is the entry's tail after some prefix rows; match_*: finite agreement only.
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A334218: Triangle read by rows: T(n,k) is the number of permutations of 1..n arranged in a circle with exactly k descents.
(identification)
1 · 1 · 0, 2 · 0, 3, 3 … row sums 1, 1, 2, 6, 24, 120, 720, 5040, …