26819

Appears in sequences

• Number of (n+1)X(3+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..3+1} nondecreasing, and column sums sum{i*x(i,j), i=1..n+1} nondecreasing.at n=4A233060
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..k+1} nondecreasing, and column sums sum{i*x(i,j), i=1..n+1} nondecreasing.at n=25A233062
• Number of (5+1)X(n+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..n+1} nondecreasing, and column sums sum{i*x(i,j), i=1..5+1} nondecreasing.at n=2A233066
• Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of regions in H_n.at n=21A370978