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 A178430 #20 Jan 17 2019 13:44:08 %S A178430 2,3,11,15,23,29,44,71,83,95,159,383,404,548,633,6409,8793,24146, %T A178430 25727,64436,74335,76875 %N A178430 Numbers n such that 10^n - 53 is prime. %C A178430 The next term, if it exists, is > 100000. %C A178430 See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99947". %H A178430 Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/">List of near-repdigit-related prime numbers</a>. %H A178430 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>. %e A178430 10^3 - 53 = 947 which is a prime number. %t A178430 m=1000; For[n=1, n<m, If[PrimeQ[10^n-53], Print[n]]; n++ ] %o A178430 (PARI) is(n)=ispseudoprime(10^n-53) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A178430 Cf. A108330, A108328. %K A178430 more,nonn %O A178430 1,1 %A A178430 _Robert Price_, Dec 21 2010 %E A178430 Corrected terms a(17) and a(18) by _Robert Price_, Dec 24 2010 %E A178430 a(20-22)=64436,74335,76875 from _Robert Price_, May 29 2011