149943domain: NAppears in sequencesa(n) = sigma_3(n^3)/sigma(n^3).at n=7A077454a(n)=2*(4^n-1)/denominator(B(2n)) where B(k) denotes the k-th Bernoulli number.at n=15A090648Numbers of the form (2^(i*j)-1)/((2^i-1)*(2^j-1)) where gcd(i,j) = 1.at n=15A112674a(n) are the denominators corresponding to A370825(n).at n=29A370826