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 A307114 #13 Mar 25 2019 19:24:10 %S A307114 27720,50400,75600,85680,95760,105840,115920,120120,128520,141120, %T A307114 143640,176400,180180,184800,205920,207900,214200,218400,235620, %U A307114 239400,264600,289800,292320,299880,308880,312480,314160,351120,371280,372960,414960,425040,438480 %N A307114 Primitive 4-abundant numbers: Numbers k such that sigma(k) > 4k (A068404) all of whose proper divisors d are 4-deficient numbers (having sigma(d) < 4d). %C A307114 Analogous to A071395 with abundancy index 4 instead of 2. %D A307114 Paul Erdős and János Surányi, Topics in the Theory of Numbers, New York: Springer, 2003, p. 243. %H A307114 Amiram Eldar, <a href="/A307114/b307114.txt">Table of n, a(n) for n = 1..10000</a> %H A307114 Graeme L. Cohen, <a href="https://doi.org/10.1090/S0025-5718-1984-0744936-X ">Primitive alpha-abundant numbers</a>, Mathematics of Computation, Vol. 43, No. 167 (1984), pp. 263-270. %H A307114 Paul Erdős, <a href="https://users.renyi.hu/~p_erdos/1956-08.pdf">On additive arithmetical functions and applications of probability to number theory</a>, Proceedings of the International Congress of Mathematicians, 1954, Amsterdam, Vol. 3 (1956), pp. 13-19. %H A307114 Paul Erdős, <a href="http://pldml.icm.edu.pl/pldml/element/bwmeta1.element.bwnjournal-article-aav5i1p25bwm">Remarks on number theory. I: On primitive alpha-abundant numbers</a>, Acta Arithmetica., Vol. 5, No. 1 (1959), pp. 25-33, <a href="https://users.renyi.hu/~p_erdos/1959-20.pdf">alternative link</a>. %t A307114 Select[Range@500000, DivisorSigma[1, #] > 4 # && Times @@ Boole@ Map[DivisorSigma[1, #] < 4 # &, Most@ Divisors@ #] == 1 &] (* after _Michael De Vlieger_ at A071395 *) %Y A307114 Cf. A000203, A068404, A071395. %K A307114 nonn %O A307114 1,1 %A A307114 _Amiram Eldar_, Mar 25 2019