A002894
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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A069466: Triangle T(n, k) of numbers of square lattice walks that start and end at origin after 2*n steps and contain exactly k steps to the east, possibly touching origin at intermediate stages.
(match row sums)
1 · 2, 2 · 6, 24, 6 · 20, 180, 180, 20 … row sums 1, 4, 36, 400, 4900, 63504, 853776, …