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 A218409 #27 May 15 2023 14:34:34 %S A218409 42,3472,56896,544635,2056320,4021920,4357080,6420960,234852352, %T A218409 1980840960,19017782784,21231974400,60129083392,962070839296, %U A218409 47911115564928,53603154468864,46152495793603584,243298521749451168,8785228837239816192 %N A218409 Numbers k for which sigma(k)/k - 2/7 is an integer. %C A218409 a(14) > 10^11. - _Donovan Johnson_, Oct 31 2012 %C A218409 a(15) > 10^12. - _Giovanni Resta_, Nov 04 2012 %C A218409 Note that there are no terms with abundancy 9/7 or 23/7. - _Michel Marcus_, Jun 25 2013 %Y A218409 Cf. A218428, A218410, A218411, A218412, A218413. %K A218409 nonn,more %O A218409 1,1 %A A218409 _Zdenek Cervenka_, Oct 28 2012 %E A218409 Missing term added and a(9)-a(13) from _Donovan Johnson_, Oct 31 2012 %E A218409 a(14) from _Giovanni Resta_, Nov 04 2012 %E A218409 More terms from _Michel Marcus_, Jun 25 2013