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