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 A058851 #13 Aug 11 2024 14:41:33 %S A058851 4,18,58,134,178,424,598,1344,4254,5998,57630,58740,59998,127404, %T A058851 424414,425344,599998,1273554,4244414,5722840,5999998,18886848, %U A058851 42683384,57725768,59999998,424650414,578107368,588254658,588349340 %N A058851 Sum of even composites up to n is palindromic. %C A058851 Sequence is 4 + 6 + 8 + 10 + 12 + 14 + ... + n. %C A058851 6*10^n-2 for n >=0 are terms. - _Chai Wah Wu_, Feb 20 2021 %H A058851 Chai Wah Wu, <a href="/A058851/b058851.txt">Table of n, a(n) for n = 1..40</a> %H A058851 P. De Geest, <a href="https://www.worldofnumbers.com/firstpal.htm#sfn5">Palindromic Sums</a> %F A058851 a(n) = 2*(1+A028553(1+n)). - _R. J. Mathar_, Sep 09 2015 %Y A058851 Cf. A028553, A028554. %K A058851 nonn,base %O A058851 1,1 %A A058851 _Patrick De Geest_, Dec 15 2000