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 A384841 #14 Jun 16 2025 15:27:36 %S A384841 14412,17640,25581,25623,25659,26208,30240,31110,31380,31500,32340, %T A384841 32736,32760,34958,35112,44211,44343,45048,45324,45444,46578,48090, %U A384841 49368,51674,52045,52290,53103,53127,53460,54000,54180,59400,59940,60228,60903,60914,60987,61920,62340,62370 %N A384841 Numbers k for which sigma(k - x) + sigma(k + x) = 8*k has at least one nonnegative solution. %H A384841 Michel Marcus, <a href="/A384841/b384841.txt">Table of n, a(n) for n = 1..100</a> %o A384841 (PARI) isok(k) = for (x=0, k-1, if (sigma(k - x) + sigma(k + x) == 8*k, return(1))); %Y A384841 Cf. A000203 (sigma), A027687 (a subsequence). %Y A384841 Cf. A383268, A384838, A384839, A384840. %Y A384841 Cf. A383758. %K A384841 nonn %O A384841 1,1 %A A384841 _Michel Marcus_, Jun 10 2025