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 A250289 #13 Dec 24 2014 23:30:06 %S A250289 20,24,26,34,38,40,64,72,74,114,118,144,192 %N A250289 Numbers n such that the numerator of Bernoulli(n) (A027641(n)) is a semiprime. %H A250289 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha134.htm">Factorizations of many number sequences</a> %H A250289 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha1341.htm">Factorizations of many number sequences</a> %H A250289 <a href="http://homes.cerias.purdue.edu/~ssw/bernoulli/index.html">Factorization of Bernoulli and Euler numbers</a> %e A250289 a(1) = 20 so the numerator of Bernoulli(20) = 174611 = 283 * 617 is a semiprime. %Y A250289 Cf. A092132. %K A250289 nonn %O A250289 1,1 %A A250289 _Eric Chen_, Dec 24 2014