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 A093151 #9 Mar 31 2012 10:32:40 %S A093151 1,13,169,1890,20216,210824,2167819,22119495,224576508,2272476724, %T A093151 22940979719,231196075659,2326967290816,23397529216327, %U A093151 235077715264515,2360380831212204,23688221424314913,237630022857420415,2382971166402199310,23889590198849417292 %N A093151 Number of odd composites 1 mod 4 less than 10^n. %F A093151 Count odd composites 1 mod 4 less than 10^n %F A093151 For n>1, a(n) = 25*10^(n-2) - 1 - A091098(n). - _Max Alekseyev_, May 30 2007 %e A093151 Below 10^2 there are 13 odd composites so a(2)=13 %Y A093151 Cf. A093152 A093153 A091295 A091098 A091099. %K A093151 nonn %O A093151 1,2 %A A093151 _Enoch Haga_, Mar 24 2004 %E A093151 More terms from _Max Alekseyev_, May 30 2007 %E A093151 Extended by _Max Alekseyev_, Oct 13 2009