548856domain: NAppears in sequencesNumbers n such that sigma(phi(n)) = n.at n=9A018784Numbers k such that sigma(phi(k)) == 0 (mod k).at n=10A067144Smret suoiverp eht fo mus fo esrever.at n=11A112296Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically.at n=26A207064