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 A137877 #13 Dec 17 2019 07:37:43
%S A137877 1,4,6,10,11,15,24,29,45,46,49,59,64,71,90,104,111,116,119,126,130,
%T A137877 144,155,165,176,181,185,196,199,204,214,225,231,235,241,249,251,266,
%U A137877 274,276,279,301,314,319,325,326,350,364,365,370,386,396,406,416,420,431
%N A137877 Numbers k such that 18*k - 1 and 18*k + 1 are twin primes.
%H A137877 Amiram Eldar, <a href="/A137877/b137877.txt">Table of n, a(n) for n = 1..10000</a>
%e A137877 1 is in the sequence since 18*1 - 1 = 17 and 18*1 + 1 = 19 are twin primes.
%t A137877 q=18; lst={}; Do[r=n*q; If[PrimeQ[r-1]&&PrimeQ[r+1], AppendTo[lst, n]], {n, 1, 10^3}]; lst (* _Vladimir Joseph Stephan Orlovsky_, Aug 07 2008 *)
%Y A137877 Cf. A124519, A135023, A135368, A137876.
%K A137877 nonn
%O A137877 1,2
%A A137877 _Zak Seidov_, Feb 19 2008