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 A252997 #39 Mar 18 2022 10:46:40 %S A252997 218,189648,720240,119967120,129705984,517941905,707902440,1321744320, %T A252997 98890370304,99080219520,119922568640,139834382688,347612467648, %U A252997 580542318720,952717920000,1064902900320,1153644808680,2255573174400,3903820736256,6859688278905,10944640212480,14424196864000 %N A252997 Numbers n such that sigma(x) - x = n has at least two solutions, with each x having the same squarefree kernel, where sigma(x) is the sum of divisor function (A000203). %C A252997 Numbers n such that n = A001065(j) = A001065(k) and A007947(j) = A007947(k), where j != k. %H A252997 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_774.htm">Prime Puzzle 774. S(i) and Rad(i)</a>, The Prime Puzzles and Problems Connection. %e A252997 218 is the sum of proper divisors of 250 and 160, and rad(250) = rad(160) = 10, hence 218 is in the sequence with j=250 and k=160. %e A252997 Other examples of n and j, k: %e A252997 For n = 189648, j = 95832, k = 85536. %e A252997 For n = 720240, j = 288120, k = 246960. %e A252997 For n = 119967120, j = 38755080, k = 34398000. %e A252997 For n = 129705984, j = 71614464, k = 60424704. %Y A252997 Cf. A001065 (sum of proper divisors of n), A007947 (squarefree kernel of n). %Y A252997 Cf. A048138, A152454, A254035. %K A252997 nonn %O A252997 1,1 %A A252997 _Naohiro Nomoto_, Dec 25 2014 %E A252997 a(6) onward from _Fred Schneider_, Feb 07 2015