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 A187711 #18 Jun 27 2024 22:15:50
%S A187711 2,3,5,7,10,11,13,17,19,20,23,29,31,33,37,40,41,43,47,53,59,61,67,71,
%T A187711 73,76,79,83,89,97,101,103,107,109,113,127,131,136,137,139,145,149,
%U A187711 151,157,163,167,173,179,181,191,193,197,199,207,211,223,227,229,233,239,241,251,257,261,263,269,271,277
%N A187711 Integers k which equal (product of divisors of k) mod (sum of divisors of k).
%H A187711 G. C. Greubel, <a href="/A187711/b187711.txt">Table of n, a(n) for n = 1..10000</a>
%F A187711 { k : k = A187680(k) }.
%p A187711 isA187711 := proc(n) is(A187680(n) = n) end proc:
%p A187711 for n from 2 to 300 do if isA187711(n) then printf("%d,",n) ; end if; end do: # _R. J. Mathar_, Mar 17 2011
%t A187711 Select[Range[300], Mod[#^(DivisorSigma[0, #]/2), DivisorSigma[1, #]] == # &] (* _G. C. Greubel_, Nov 05 2018 *)
%Y A187711 Cf. A000203, A007955, A187680.
%K A187711 nonn
%O A187711 1,1
%A A187711 _Juri-Stepan Gerasimov_, Mar 17 2011