39436domain: NAppears in sequencesComposite and even n such that phi(n) * sigma(n) is one less than a square.at n=26A015721Number of nX5 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=8A301320