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 A130839 #2 Mar 31 2012 13:23:38 %S A130839 1,0,0,1,1,3,2,7,5,5,8,14,14,8,20,26,32,15,40,40,45,22,47,65,23,77,94, %T A130839 75,63,98,122,37,135,196,120,148,188,117,216,55,226,231,187,206,377, %U A130839 187,310,338,286,366,83,483,375,99,454,405,683,284,598 %N A130839 Sequence related to factorizations and prime signatures: a(1) = 1; for n>1,a(n) = A108464(n) - 2*A050322(n). %Y A130839 Cf. A131802 A050322. %K A130839 easy,nonn %O A130839 1,6 %A A130839 _Alford Arnold_, Jul 19 2007