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 A204829 #19 Feb 16 2025 08:33:16 %S A204829 6,12,18,20,24,28,30,36,40,42,48,54,56,60,66,70,72,78,80,84,88,90,96, %T A204829 100,102,104,108,112,114,126,132,138,140,144,150,156,160,162,168,174, %U A204829 176,186,192,196,198,200,204,208,210,216,220,222,224,228,234,246,252 %N A204829 Numbers with abundancy 2 <= a < 3. %C A204829 Numbers m such that 2 <= sigma(m) / m < 3. %C A204829 Supersequence of A000396 (perfect numbers). %H A204829 Jaroslav Krizek and T. D. Noe, <a href="/A204829/b204829.txt">Table of n, a(n) for n = 1..1000</a> %H A204829 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Abundancy.html">Abundancy</a> %H A204829 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AbundantNumber.html">Abundant Number</a> %e A204829 Number 70 is in sequence because sigma(70) / 70 = 144 / 70, which is between 2 and 3. %Y A204829 Cf. A204828 (abundant numbers with abundancy 3 <= a < 4). %K A204829 nonn %O A204829 1,1 %A A204829 _Jaroslav Krizek_, Jan 22 2012