39188

Appears in sequences

• Number of symmetrical planar partitions of n (planar partitions (A000219) that when regarded as 3-D objects have just one symmetry plane).at n=40A000784
• Number of triangles in an n X n unit grid that have minimal possible area (of 1/2).at n=15A088658
• Number of (n+6)X(n+6) 0..1 matrices with each 7X7 subblock idempotent.at n=7A224580
• Number of (n+1) X (2+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=2A234544
• Number of (n+1) X (3+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=1A234545
• T(n,k) is the number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=7A234549
• T(n,k) is the number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=8A234549
• Coordination sequence for (2,4,6) tiling of hyperbolic plane.at n=30A265061
• a(n) = Sum_{i=1..n, j=1..n, gcd(i,j)=2} (n+1-i)*(n+1-j).at n=30A331761