3472494301domain: NAppears in sequencesCyclotomic polynomials at x=-3.at n=25A020502Numbers of the form (3^s+1)/(3^r+1) for s > 1, 1 <= r <= s-1.at n=26A079672a(n) = A015518(A032742(n)) / A015518(A054576(n)).at n=49A280691a(n) = sigma_10(n^2)/sigma_5(n^2).at n=8A373105