54825domain: NAppears in sequencesStructured heptagonal anti-diamond numbers (vertex structure 7).at n=24A100186Numbers n such that sigma(2*phi(n)) = 2*sigma(n).at n=24A137733Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 or 00000001.at n=9A259636