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 A057959 #18 Nov 05 2019 05:54:45 %S A057959 4,34,36,215,258,288,1711,2785,3708,4572,4873,18986,29509,42005,45534, %T A057959 234272,411232,2074123,2225480,2841251,3728941,4590401,17643216, %U A057959 72349270,176262062,219311147,426454179,444875288,1457527586 %N A057959 Sum of composite numbers up to n is palindromic. %C A057959 Sequence is 4 + 6 + 8 + 9 + 10 + 12 + ... + n. %H A057959 Patrick De Geest, <a href="http://www.worldofnumbers.com/firstpal.htm#sfn3">Palindromic Sums</a>. %H A057959 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_089.htm">Puzzle 89</a>, The Prime Puzzles & Problems Connection. %F A057959 a(n) = A002808(A053779(n)). - _R. J. Mathar_, Sep 09 2015 %Y A057959 Cf. A002113, A002808, A053779, A053780. %K A057959 base,nonn %O A057959 1,1 %A A057959 _G. L. Honaker, Jr._ and _Patrick De Geest_, Nov 15 2000