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 A291550 #30 Jan 24 2023 02:46:31 %S A291550 666030256,696630544,967947856,1031796176,2840437756,3156691844, %T A291550 4150593232,4213181968,4796703664,4855069456,10168398448,11159012552, %U A291550 33707179456,33844856128,53151801712,55270703248,62393407792,65270990608,107122129216,107620508608,284624443948,287125556692 %N A291550 Even amicable pairs whose sum is not divisible by 9. %C A291550 Most even amicable pairs have a sum which is divisible by 9; for instance, the sum of (220, 284) is 504. %H A291550 Amiram Eldar, <a href="/A291550/b291550.txt">Table of n, a(n) for n = 1..1134</a> (terms below 10^20) %H A291550 Elvin Lee, <a href="https://doi.org/10.1090/S0025-5718-1969-0248074-6">On divisibility by nine of the sums of even amicable pairs</a>, Math. Comp. 23 (1969), 545-548. %e A291550 (666030256, 696630544) is an amicable pair whose sum is 571750000640 == 8 (mod 9). %Y A291550 Cf. A063990, A180164, A259180, A291422. %K A291550 nonn,tabf %O A291550 1,1 %A A291550 _Michel Marcus_, Aug 26 2017