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 A058323 #23 Jul 09 2015 05:56:46
%S A058323 23921257,32611897,33215597,35650007,44201617,49945837,51616717,
%T A058323 70350487,70687937,74816107,78789707,86066047,99641917,101568287,
%U A058323 129031187,146922077,149568217,151779517,153921017,156793337,162881627
%N A058323 Initial prime in set of 4 consecutive primes with common gap 42.
%C A058323 All a(n) == 7 mod 10. - _Robert Israel_, May 13 2015
%H A058323 Zak Seidov, <a href="/A058323/b058323.txt">Table of n, a(n) for n = 1..1000</a>
%H A058323 <a href="/index/Pri#primes_AP">Index entries for sequences related to primes in arithmetic progressions</a>
%t A058323 d[x_] := Prime[x+1]-Prime[x] {k1=42, k2=42, k3=42} k=0 Do[If[Equal[d[n], k1]&&Equal[d[n+1], k2]&& Equal[d[n+2], k3], k=k+1; Print[{k, n, Prime[n], Prime[n+1], Prime[n+2], Prime[n+3]}]], {n, 1, 10000000}]
%t A058323 Transpose[Select[Partition[Prime[Range[9000000]], 4, 1], Union[Differences[#]]=={42}&]][[1]] (* _Vincenzo Librandi_, Jun 21 2015 *)
%Y A058323 Analogous sequences (with differences in square brackets): A033451 [6], A033447 [12], A033448 [18], A052242 [24], A052243 [30], A058252 [36].
%K A058323 nonn
%O A058323 1,1
%A A058323 _Harvey P. Dale_, Dec 12 2000
%E A058323 More terms from _Labos Elemer_, Jan 11 2002
%E A058323 Definition corrected by _Robert Israel_, May 13 2015
%E A058323 Definition edited by _Zak Seidov_, Jun 21 2015
%E A058323 Offset changed 0 -> 1 by _Zak Seidov_, Jun 21 2015