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 A286661 #13 Feb 16 2025 08:33:45
%S A286661 3,41,43,641,643,8641,108643,18161412108641,
%T A286661 525048464442403836343230282624222018161412108643,
%U A286661 646260585654525048464442403836343230282624222018161412108641
%N A286661 Primes of form A038396(n) - 1 or A038396(n) + 1.
%C A286661 a(11) = A038396(42) + 1 = 84...43, a(12) = A038396(54) + 1 = 108...43;
%C A286661 a(13) = A038396(185) + 1 = 370...43, a(14) = A038396(199) - 1 = 398...41;
%C A286661 a(15) = A038396(224) + 1 = 448...43, a(16) = A038396(248) - 1 = 496...41;
%C A286661 a(17) = A038396(346) - 1 = 692...41, a(18) = A038396(947) - 1 = 1894...41.
%C A286661 a(19) (if it exists) will be more than A038396(3000).
%C A286661 a(2) and a(3) are a pair of twin primes, a(4) and a(5) also.
%H A286661 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConsecutiveNumberSequences.html">Consecutive Number Sequences</a>
%t A286661 Select[#, PrimeQ] &@ Flatten@ Table[{# - 1, # + 1} &@ FromDigits@ Flatten@ Reverse@ Take[#, n], {n, Length@ #}] &@ Array[IntegerDigits[2 #] &, 40] (* _Michael De Vlieger_, May 14 2017 *)
%Y A286661 Cf. A038396, A019520, A210734.
%K A286661 nonn,base
%O A286661 1,1
%A A286661 _XU Pingya_, May 12 2017