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 A331840 #36 Sep 06 2023 13:41:30
%S A331840 1,4,5,7,8,12,21,28,29,43,48,50,54,56,57,60,63,67,68,70,75,76,89,90,
%T A331840 106,109,116,118,119,126,131,138,139,141,145,151,152,155,160,166,181,
%U A331840 183,189,196,207,228,232,238,244,249,250,252,259,263,270,280,285,287
%N A331840 Numbers k such that 30*k-13, 30*k-11 are twin primes.
%C A331840 All twin primes > 7 have the form 30*k-{13,11}, or 30*k +-1 (A176114), or 30*k+{11,13} (A089160).
%C A331840 All twin primes > 7 with least significant decimal digit 7 have the form 30*k-13.
%C A331840 All twin primes > 7 with least significant decimal digit 3 have the form 30*k+13.
%F A331840 a(n) = A089161(n)+1.
%e A331840 1 is a term because 1*30 - 13 = 17 = prime(6) and 1*30 - 11 = 19 = prime(7).
%e A331840 4 is a term because 4*30 - 13 = 107 = prime(28) and 4*30 - 11 = 109 = prime(29).
%e A331840 5 is a term because 5*30 - 13 = 137 = prime(33) and 5*30 - 11 = 139 = prime(34).
%t A331840 Select[Range[300], And @@ PrimeQ[30*# - {11, 13}] &] (* _Amiram Eldar_, Feb 29 2020 *)
%o A331840 (Rexx)
%o A331840 S = 1
%o A331840 do N = 2 while length( S ) < 255
%o A331840 if NOPRIME( N*30 -13 ) then iterate N
%o A331840 if NOPRIME( N*30 -11 ) then iterate N
%o A331840 S = S || ',' N
%o A331840 end N
%o A331840 say S
%o A331840 (PARI) isok(k) = isprime(30*k-13) && isprime(30*k-11); \\ _Michel Marcus_, Feb 29 2020
%Y A331840 Cf. A089160, A089161, A176114, A332772.
%Y A331840 Cf. A000040, A001097, A002822, A132242, A282323, A282324.
%K A331840 nonn,easy
%O A331840 1,2
%A A331840 _Frank Ellermann_, Feb 26 2020