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 A087641 #38 Feb 16 2025 08:32:51 %S A087641 29,101,5,9419,909287,325267931,678771479,1107819732821, %T A087641 170669145704411,3324648277099157,789795449254776509 %N A087641 Start of the first sequence of exactly n consecutive pairs of twin primes. %C A087641 Start of the smallest twin prime clusters of order n such that the following and preceding two primes must be neither twin primes between themselves nor with the ends of the string. - Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 22 2006 %C A087641 Sequences of n consecutive pairs of twin primes are called twin prime clusters of order n. Here (and in the sequences A035789, ..., A035795) it is requested that the order be exactly n, i.e., the preceding prime and the following prime must not be (upper resp. smaller) member of another twin prime pair. Note that a(3)=5 is preceded by 3 which is member of the twin prime pair (3,5) but not upper member of a preceding twin prime pair. Since it cannot happen elsewhere that P2=P3-2 if P3=P4-2 (using notations of A179067 and A035791), there is no condition imposed on P3-P2, and the condition on P2-P1 is also satisfied for P3=5. This sequence lists the starting prime of the cluster corresponding to the first occurrence of n in A179067. - _M. F. Hasler_, May 04 2015 %H A087641 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a035789.txt">Consecutive pairs of twin primes.</a> FORTRAN program. %H A087641 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_122.htm">Puzzle 122. Consecutive Twin primes</a>, The Prime Puzzles and Problems Connection. %H A087641 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TwinPrimeCluster.html">Twin Prime Cluster</a> %e A087641 a(6)=325267931 is the starting point of the first occurrence of 6 consecutive pairs of twin primes: (325267931 325267933) (325267937 325267939) (325267949 325267951) (325267961 325267963) (325267979 325267981) (325267991 325267993). %Y A087641 Cf. A001359, A111950. %Y A087641 The sequence consists of the initial terms of A035789, A035790, A035791, A035792, A035793, A035794, A035795, A263205, A259034. %K A087641 more,nonn %O A087641 1,1 %A A087641 _Hugo Pfoertner_, Sep 15 2003 %E A087641 Extended by _Jud McCranie_ %E A087641 a(8)-a(10) from Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 22 2006 %E A087641 a(11) found by Gabor Levai in October 2011 (see Rivera), added by _Dmitry Kamenetsky_, Dec 15 2018