270720

Appears in sequences

• a(n)=16*n!/(253*43!).at n=1A157988
• Number of ways to place 5 points on an n X n square grid so that no more than 2 points are on a vertical or horizontal straight line.at n=5A279439
• Triangle read by rows: T(n, k) is the number of ways to place k points on an n X n square grid so that no more than 2 points are on a vertical or horizontal straight line.at n=39A279445
• a(n) = Sum_{k=0..n} 2^k * binomial(k+2,2) * binomial(2*k,2*(n-k)).at n=7A391875