200321

Appears in sequences

• Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 10001-11111 pattern in any orientation.at n=16A147085
• Number of nondecreasing -n..n vectors of length 5 whose dot product with some lexicographically greater or equal nondecreasing -n..n vector equals 5.at n=13A226426