Table read by rows: T(n,k) = number of k-sided polygons in a cross with width 3 and height n (see Comments in A331455 for definition) for k = 3,4,5.

A330848

Table read by rows: T(n,k) = number of k-sided polygons in a cross with width 3 and height n (see Comments in A331455 for definition) for k = 3,4,5.