2908308

Appears in sequences

• Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 2Xn array.at n=11A220936
• a(n) = practical(2^n) where practical(n) is the n-th practical number (A005153).at n=18A225316