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 A096505 #13 Jun 06 2024 03:49:09
%S A096505 3,5,7,23,67,89,223,666667,22222223,66666667,666666667,22222222223,
%T A096505 66666666667,88888888888889,88888888888888889,66666666666666666667,
%U A096505 66666666666666666666667,88888888888888888888888888888888889,222222222222222222222222222222222223
%N A096505 Primes of the form 1 + repdigit. Primes whose totient is a repdigit.
%H A096505 Amiram Eldar, <a href="/A096505/b096505.txt">Table of n, a(n) for n = 1..38</a>
%e A096505 89 is a term since it is a prime, and its totient, 88, is a decimal repdigit.
%t A096505 s = {3, 5, 7}; Do[r = (10^k - 1)/9; Do[p = m * r + 1; If[PrimeQ[p], AppendTo[s, p]], {m, {2, 6, 8}}], {k, 2, 50}]; s (* _Amiram Eldar_, Jun 06 2024 *)
%Y A096505 Cf. A000010, A010785, A096503, A096504.
%K A096505 base,nonn
%O A096505 1,1
%A A096505 _Labos Elemer_, Jul 12 2004
%E A096505 a(19) from _Amiram Eldar_, Jun 06 2024