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 A029561 #15 Aug 11 2014 22:45:15
%S A029561 1595,6785,53867,67727,102377,296003,740027,961877,998867,1048817,
%T A029561 1270055,1365377,4086227,7715567,12266267,15017921,24960245,33759467,
%U A029561 34918697,36265385,38342397,41048777,44535647,48056087,56264987,58515347
%N A029561 Quasi-Carmichael numbers to base 2: squarefree composites n such that prime p|n ==> p-2|n-2.
%C A029561 These are called 2-Korselt numbers by Beouallegue et al.
%H A029561 Giovanni Resta, <a href="/A029561/b029561.txt">Table of n, a(n) for n = 1..393</a> (terms < 10^12)
%H A029561 <a href="/index/Ca#Carmichael">Index entries for sequences related to Carmichael numbers.</a>
%H A029561 K. Bouallegue, O. Echi, R. G. E. Pinch, <a href="http://dx.doi.org/10.1142/S1793042110002922 ">Korselt numbers and sets</a>, Int. J. Numb. Theory 6 (2) (2010) 257-269
%t A029561 qcm[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n; Length[p] > 1 && Max[e] == 1 && ! MemberQ[p, d] && Max@ Mod[n-d, p-d] == 0]; Select[Range[10^5], qcm[#, 2] &] (* _Giovanni Resta_, May 21 2013 *)
%Y A029561 Cf. A120944, A002997.
%K A029561 nonn
%O A029561 1,1
%A A029561 _David W. Wilson_