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 A128471 #29 Apr 04 2025 07:49:10
%S A128471 7,37,67,97,127,157,187,217,247,277,307,337,367,397,427,457,487,517,
%T A128471 547,577,607,637,667,697,727,757,787,817,847,877,907,937,967,997,1027,
%U A128471 1057,1087,1117,1147,1177,1207,1237,1267,1297,1327,1357,1387,1417,1447,1477
%N A128471 a(n) = 30*n + 7.
%C A128471 30*n + 7 -/+ 2 is a multiple of 3 or 5. For n > 0, this number is not prime. So with the exception of a(0), no a(n) is a member of a twin prime pair.
%C A128471 Except for 7, these numbers cannot be written as sum or difference of two primes. - _Arkadiusz Wesolowski_, Jan 08 2012
%H A128471 Albert van der Horst, <a href="http://home.hccnet.nl/a.w.m.van.der.horst/hcc96.txt">Counting Twin Primes</a>.
%H A128471 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A128471 a(n) = 2*a(n-1) - a(n-2). - _Vincenzo Librandi_, Sep 05 2010
%F A128471 G.f.: (7+23*x)/(1-x)^2. - _R. J. Mathar_, Sep 05 2010
%F A128471 E.g.f.: exp(x)*(7 + 30*x). - _Elmo R. Oliveira_, Apr 04 2025
%t A128471 Range[7,7000,30] (* _Vladimir Joseph Stephan Orlovsky_, Jun 18 2011 *)
%t A128471 LinearRecurrence[{2,-1},{7,37},50] (* _Harvey P. Dale_, Jul 31 2024 *)
%o A128471 (PARI) A128471(n)={ return(30*n+7) ; }
%o A128471 for(n=0,30,print1(A128471(n)",")) ; /* _R. J. Mathar_, Sep 05 2010 */
%K A128471 easy,nonn
%O A128471 0,1
%A A128471 _Cino Hilliard_, May 06 2007
%E A128471 Comment clarified by _Robert Israel_, offset set to zero by _R. J. Mathar_, Sep 05 2010