17099809

Appears in sequences

• Number of (n+2)X(3+2) 0..1 arrays x(i,j) with every row sum{j*x(i,j), j=1..3+2} equal, and every column sum{i*x(i,j), i=1..n+2} equal, with upper left element zero.at n=20A232649
• Number of (n+2)X(4+2) 0..1 arrays x(i,j) with every row sum{j*x(i,j), j=1..4+2} equal, and every column sum{i*x(i,j), i=1..n+2} equal, with upper left element zero.at n=20A232650