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 A266512 #58 Mar 02 2025 23:35:18 %S A266512 2,3,47,5,18713,7,12003179,17,1480028129,13,1542186111157, %T A266512 41280160361347,660287401247633,10421030292115097,3112462738414697093, %U A266512 996689250471604163,258406392900394343851,824871967574850703732309,9425346484752129657862217,824871967574850703732303 %N A266512 Smallest prime starting a (nonsingular) symmetric n-tuplet of the shortest span (=A266511(n)). %C A266512 A similar sequence that allows singular symmetric n-tuples is given in A266583. %C A266512 a(1)-a(10) from _Natalia Makarova_ %C A266512 a(11)-a(14), a(16) from _Dmitry Petukhov_ %C A266512 a(15), a(17) from Jaroslaw Wroblewski %H A266512 N. Makarova and Carlos Rivera, <a href="http://www.primepuzzles.net/problems/prob_062.htm">Problem 62. Symmetric k-tuples of consecutive primes</a>, The Prime Puzzles & Problems Connection. %H A266512 Natalia Makarova and Vladimir Chirkov, <a href="/A266512/a266512_1.txt">Theoretical patterns with a minimal diameter for a(2) - a(50)</a> %H A266512 Dmitry Petukhov, Anton Nikonov and Ruslan Vikulov, <a href="https://dxdy.ru/post1668659.html#p1668659">found a(19)</a> and <a href="https://dxdy.ru/post1671408.html#p1671408">proof of that is smallest</a> (in Russian), posts in Symmetric tuples of consecutive primes on dxdy blog. %F A266512 a(n) = A000040(A266584(n)). %Y A266512 Cf. A055380, A065688, A175309, A266511, A266583, A266584. %K A266512 nonn,more,hard %O A266512 1,1 %A A266512 _Max Alekseyev_, Dec 30 2015 %E A266512 a(18) from Jaroslaw Wroblewski %E A266512 a(20) from _Natalia Makarova_ and Jaroslaw Wroblewski %E A266512 a(19) from _Dmitry Petukhov_, _Anton Nikonov_ and Ruslan Vikulov, Jan 24 2025