2657666

Appears in sequences

• Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX3 array.at n=7A220276
• T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nXk array.at n=47A220279
• a(n) is the number of canonical polygons with n edges having exactly 1 line of reflection symmetry.at n=23A307455