This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A038108 #13 Sep 02 2013 12:31:52 %S A038108 0,2,6,8,13,16,22,26,34,39,48,55,62,75,82,89,103,113,126,135,149,163, %T A038108 179,190,202,220,236,252,270,288,304,320,340,360,381,403,425,443,462, %U A038108 483,508,532,556,581,604,633,655,678,709,738,761,782 %N A038108 Number of prime pairs {p,q}, such that pq < n^2. %C A038108 Number of semiprimes (A001358) < n^2. [_Michel Marcus_, Sep 02 2013] %e A038108 a(3)=2 because only the prime pairs (2,2) and (2,3) form products < 9. %o A038108 (PARI) a(n) = {sqn = n^2; idp = primepi(sqn\2); nbp = 0; for (i = 1, idp, p = prime(i); for (j = 1, i, if (p * prime(j) < sqn, nbp++););); nbp;} \\ _Michel Marcus_, Sep 02 2013 %Y A038108 Cf. A205726. %K A038108 nonn %O A038108 2,2 %A A038108 Joe K. Crump (joecr(AT)carolina.rr.com)