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 A029556 #14 May 21 2013 11:16:15
%S A029556 187,247,4807,12331,21307,32227,50167,61087,62647,82087,89947,101959,
%T A029556 113839,118327,127303,137287,140767,141457,168199,187207,193591,
%U A029556 214819,234247,235807,259207,283943,306907,358423,369799,396727,422719,424057
%N A029556 Quasi-Carmichael numbers to base 7: squarefree composites n such that (n,2*3*5) = 1 and prime p|n ==> p-7|n-7.
%C A029556 If multiples of 2, 3 and 5 are not excluded, then terms like 15, 55, 715, 759, 1495,... belong to the sequence. - _Giovanni Resta_, May 21 2013
%H A029556 Giovanni Resta, <a href="/A029556/b029556.txt">Table of n, a(n) for n = 1..8274</a> (terms < 10^12)
%H A029556 <a href="/index/Ca#Carmichael">Index entries for sequences related to Carmichael numbers.</a>
%t A029556 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[#, 7] &] (* _Giovanni Resta_, May 21 2013 *)
%K A029556 nonn
%O A029556 1,1
%A A029556 _David W. Wilson_