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 A034780 #14 May 12 2018 11:44:57
%S A034780 7,13,25,27,37,43,45,49,57,67,73,79,84,87,93,97,115,127,139,142,160,
%T A034780 163,169,175,177,193,199,205,207,213,234,235,253,255,258,265,267,277,
%U A034780 279,295,298
%N A034780 Numbers k such that A034693(k) = 4.
%H A034780 R. J. Mathar, <a href="/A034780/b034780.txt">Table of n, a(n) for n = 1..656</a>
%t A034780 Position[#, 4] &@ Table[k = 1; While[! PrimeQ[k n + 1], k++]; k, {n, 300}] // Flatten (* _Michael De Vlieger_, Mar 02 2017 *)
%Y A034780 Cf. A034693, A034694.
%K A034780 nonn
%O A034780 1,1
%A A034780 _Labos Elemer_