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 A077792 #33 Mar 26 2020 11:13:04
%S A077792 3,15,171,189,547,713,2155,3595,13517,60465
%N A077792 Numbers k such that (10^k - 1)/3 + 5*10^floor(k/2) is a palindromic wing prime (a.k.a. near-repdigit palindromic prime).
%C A077792 Prime versus probable prime status and proofs are given in the author's table.
%C A077792 a(11) > 2*10^5. - _Robert Price_, Apr 21 2016
%D A077792 C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.
%H A077792 Patrick De Geest, World!Of Numbers, <a href="http://www.worldofnumbers.com/wing.htm#pwp383">Palindromic Wing Primes (PWP's)</a>
%H A077792 Makoto Kamada, <a href="https://stdkmd.net/nrr/3/33833.htm#prime">Prime numbers of the form 33...33833...33</a>
%H A077792 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%F A077792 a(n) = 2*A183177(n) + 1.
%e A077792 15 is a term because (10^15 - 1)/3 + 5*10^7 = 333333383333333.
%t A077792 Do[ If[ PrimeQ[(10^n + 15*10^Floor[n/2] - 1)/3], Print[n]], {n, 3, 13600, 2}] (* _Robert G. Wilson v_, Dec 16 2005 *)
%Y A077792 Cf. A004023, A077775-A077798, A107123-A107127, A107648, A107649, A115073, A183174-A183187.
%K A077792 more,nonn,base
%O A077792 1,1
%A A077792 _Patrick De Geest_, Nov 16 2002
%E A077792 a(10) from _Robert Price_, Apr 21 2016
%E A077792 Name corrected by _Jon E. Schoenfield_, Oct 31 2018