155739domain: NAppears in sequencesa(n) = floor(Li(2^n)), where Li(x) is the integral from 0 to x of dt/log(t).at n=20A089897Magic sums of 3 X 3 semimagic squares composed of squares of primes.at n=7A269344Numbers k such that k - sopfr(k) is a positive cube.at n=42A389889