25338

Appears in sequences

• Consider a room of size r X s where rs = 2n and 1 <= r, 1 <= s; count ways to arrange n Tatami mats in room; a(n) = total number of ways for all choices of r and s. Two arrangements are distinguished if one is a rotation or reflection of the other.at n=24A067925
• Composite numbers k such that D(k) == 3 (mod k), where D(k) is the k-th central Delannoy number (A001850).at n=9A330203