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 A243592 #9 Jun 14 2014 13:25:43 %S A243592 1,15,33,35,45,51,65,69,77,85,87,91,95,99,105,115,119,123,133,135,141, %T A243592 143,145,153,159,161,165,175,177,185,187,195,207,209,213,215,217,221, %U A243592 231,235,245,247,249,255,259,261,265,267,285,287,295,297,299,303,315,319,321,323,325,329,335,339,341,345,357,365,369,371 %N A243592 Numbers n such that there is no indecomposable group of order n. %C A243592 Numbers n such that A090751(n) = 0. %C A243592 Includes all non-prime-power members of A051532. - _Eric M. Schmidt_, Jun 07 2014 %H A243592 Joerg Arndt, <a href="/A243592/b243592.txt">Table of n, a(n) for n = 1..506</a> %H A243592 Paul Erdős, Péter P. Pálfy, <a href="http://dx.doi.org/10.1016/S0012-365X(98)00325-2">On the orders of directly indecomposable groups</a>. Paul Erdős memorial collection. Discrete Math. 200 (1999), no. 1-3, 165-179. %K A243592 nonn %O A243592 1,2 %A A243592 _Joerg Arndt_, Jun 07 2014