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 A273971 #19 Jul 23 2025 15:40:30
%S A273971 756000,803040,1267560,1442448,1851360,2535120,3209760,3477240,
%T A273971 3926160,3969840,4413240,4664880,6094368,6840540,7617960,7783020,
%U A273971 8027880,8360352,8586900,9215640,9559200,9596520,9697380,9811620,9815400,9938160,10063200,10234224
%N A273971 Numbers y such that there exists a pair x, n, with x < y, x != n and y != n that makes {x,y,n,n} an amicable multiset.
%C A273971 We call the multiset {x,y,n,n} amicable iff sigma(x) = sigma(y) = sigma(n) = x+y+n+n. For the n values, see A273969. For the x values, see A273970.
%C A273971 If the condition x<y were dropped, the terms from A259306 would also belong here.
%H A273971 John Cerkan, <a href="/A273971/b273971.txt">Table of n, a(n) for n = 1..7515</a>
%H A273971 John Cerkan, <a href="/A273971/a273971.py.txt">Python code</a>
%e A273971 sigma(695520) = sigma(803040) = sigma(702240) = 695520 + 803040 + 702240 + 702240.
%Y A273971 Cf. A259302, A259303, A259304, A259305, A259306, A273969, A273970.
%K A273971 nonn
%O A273971 1,1
%A A273971 _John Cerkan_, Jul 17 2016