A002457
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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A008459 → D
(match row sums)
1 · 4, 2 · 9, 18, 3 · 16, 72, 48, 4 … row sums 0, 1, 6, 30, 140, 630, 2772, 12012, …