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 A078656 #14 May 31 2021 13:52:52
%S A078656 31,127,179,283,353,547,739,877,1087,1153,1297,1523,1597,1741,1823,
%T A078656 2063,2221,2749,2909,3001,3259,3517,3733,3911,4153,4421,4663,4759,
%U A078656 4943,5189,5281,5701,5801,6229,6311,6841,7109
%N A078656 a(n) = prime(k) where k = n-th prime congruent to 1 mod 10.
%H A078656 Vincenzo Librandi, <a href="/A078656/b078656.txt">Table of n, a(n) for n = 1..1000</a>
%t A078656 Prime[10Select[Range[110], PrimeQ[10# + 1] &] + 1]
%t A078656 Prime[#]&/@Select[Prime[Range[200]],NumberDigit[#,0]==1&] (* Requires Mathematica version 12 or later *) (* _Harvey P. Dale_, May 31 2021 *)
%o A078656 (PARI) pip(n,m,r) = {sr=0; forprime(x=3,n, if(x%m == r,v=prime(x); sr+=1.0/v; print1(v" "); ) ); print(); print("m="m" r="r" sr="sr); }
%Y A078656 Cf. A024912.
%K A078656 easy,nonn
%O A078656 1,1
%A A078656 _Cino Hilliard_, Dec 14 2002
%E A078656 Edited by _Robert G. Wilson v_, Dec 17 2002