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 A124140 #15 Feb 08 2022 08:00:43 %S A124140 24,78,90,224,260,264,348,570,728,846,996,1580,1692,2030,2514,3552, %T A124140 3762,4560,4648,4668,5250,5976,6448,6650,6954,8634,10458,11994,13624, %U A124140 14056,14476,16056,17064,17292,17412,18960,21712,22652,23500,24108,26940,27132,27412 %N A124140 Numbers k such that there is a bigger number m satisfying A000203(k) = A000203(m) = m + k - gcd(m,k). %C A124140 R. Mathar computed this sequence up to 15000. %e A124140 24 is in the sequence because A000203(24) = A000203(38) = 60 = 24 + 38 - gcd(24,38). %Y A124140 Cf. A000203, A124141. %K A124140 nonn %O A124140 1,1 %A A124140 _Yasutoshi Kohmoto_, Dec 01 2006 %E A124140 Edited by _Stefan Steinerberger_, Aug 14 2007 %E A124140 Terms corrected by and more terms from _Jinyuan Wang_, Feb 07 2022