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 A029559 #15 May 21 2013 11:15:00
%S A029559 1705,7015,31369,53599,77809,215635,244885,248239,346801,568879,
%T A029559 662935,898105,2151769,2240515,2782579,9480829,10665265,11219485,
%U A029559 13644085,13929205,16549579,17782879,21592289,29354329,30075565,35448439,39792379
%N A029559 Quasi-Carmichael numbers to base 4: squarefree composites n such that (n,2*3) = 1 and prime p|n ==> p-4|n-4.
%C A029559 If multiples of 2 and 3 are not excluded, then terms like 6, 10, 15, 30, 70, 130, 165,... belong to the sequence. - _Giovanni Resta_, May 21 2013
%H A029559 Giovanni Resta, <a href="/A029559/b029559.txt">Table of n, a(n) for n = 1..372</a> (terms < 10^12)
%H A029559 <a href="/index/Ca#Carmichael">Index entries for sequences related to Carmichael numbers.</a>
%t A029559 qcm[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n; Length[p] > 1 && Max[e] == 1 && d < Min[p] && And @@ IntegerQ /@ ((n - d)/(p - d))]; Select[Range[10^6], qcm[#, 4] &] (* _Giovanni Resta_, May 21 2013 *)
%K A029559 nonn
%O A029559 1,1
%A A029559 _David W. Wilson_