80560

Appears in sequences

• Expansion of (Product_{j>=1} (1-(-x)^j) - 1)^20 in powers of x.at n=9A047645
• Number of fixed polyominoes with n cells of which no four are equally spaced on a straight line.at n=16A065068
• Number of (n+1) X (n+1) -5..5 symmetric matrices with every 2 X 2 subblock having sum zero and three distinct values.at n=12A211330
• Number of vertices in a regular 2n-gon when all vertices are connect by straight lines except for the n lines joining diametrically opposite vertices.at n=19A368814