67950

Appears in sequences

• Number of n X n matrices with exactly 2 1's in each row and column, other entries 0.at n=6A001499
• Triangle read by rows: T(n,k) (n >= 0, 0 <= k <= n) gives number of {0,1} n X n matrices with all row and column sums equal to k.at n=23A008300
• Triangle read by rows: T(n,k) (n >= 0, 0 <= k <= n) gives number of {0,1} n X n matrices with all row and column sums equal to k.at n=25A008300
• Number of n X n (0,1) matrices with all column and row sums equal to 4.at n=6A058528
• Counts 3-wild partitions. In general p-wild partitions of n are defined so that they are in bijection with geometric equivalence classes of degree n algebra extensions of the p-adic field Q_p. Here two algebra extensions are equivalent if they become isomorphic after tensoring with the maximal unramified extension of Q_p.at n=15A131140
• Number of 3*n X 6 0..1 arrays with row sums 2 and column sums n.at n=1A172572
• Number of lower triangles of a 4 X 4 0..n array with no element differing from any of its horizontal or vertical neighbors by more than one.at n=10A194933
• Number of ways to place 8 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=4A279442
• 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=31A279445
• 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=46A279445