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 A092609 #15 Nov 09 2020 06:25:03
%S A092609 11,341,13981,852841,60551711,6115722811,801159688241,120975112924391,
%T A092609 21896495439314771,4182230628909121261,882450662699824586071,
%U A092609 212670609710657725243111,53380323037375089036020861
%N A092609 Product of first n primes that end in 1.
%H A092609 Robert Israel, <a href="/A092609/b092609.txt">Table of n, a(n) for n = 1..286</a>
%e A092609 a(1)= 11 = 11
%e A092609 a(2)= 11*31 = 341
%e A092609 a(3)= 11*31*41= 13981
%e A092609 a(4)= 11*31*41*61= 852841
%p A092609 Res:= NULL: p:= 1: count:= 0:
%p A092609 for n from 11 by 10 while count < 30 do
%p A092609 if isprime(n) then count:= count+1; p:= p*n; Res:= Res,p fi
%p A092609 od:
%p A092609 Res; # _Robert Israel_, Sep 16 2018
%t A092609 Rest[FoldList[Times,1,Select[Prime[Range[70]],Mod[#,10]==1&]]] (* _Harvey P. Dale_, Jun 05 2013 *)
%o A092609 (PARI) a(n) = {my(k=1, x=1); for (j=1, n, while(!isprime(10*k+1), k++); x *= (10*k+1); k++;); x;} \\ _Michel Marcus_, Nov 09 2020
%Y A092609 Cf. A030430.
%K A092609 nonn,easy
%O A092609 1,1
%A A092609 _Jorge Coveiro_, Apr 11 2004