215514

Appears in sequences

• Number of pairs of intersecting diagonals in the interior and exterior of a regular n-gon.at n=36A211380
• Number of intersections of diagonals in the interior and exterior of a regular n-gon.at n=36A211383
• Number of nX5 0..1 arrays with every element equal to 1, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.at n=8A298579