A144440
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.
-
A144440: Triangle T(n,k) by rows: T(n, k) = (3*n-3*k+1)*T(n-1, k-1) +(3*k-2)*T(n-1, k) + 3*T(n-2, k-1) with T(n, 1) = T(n, n) = 1.
(identification, match reversed triangle, match triangle)
1 · 1, 1 · 1, 11, 1 · 1, 54, 54, 1 … row sums 1, 2, 13, 110, 1249, 17816, 306619, …