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 A174352 #4 May 22 2017 11:56:40 %S A174352 1,4,5,17,20,28,173,181,331,575,1313,1754,4067,27314 %N A174352 Numbers n such that (n+1)*10^n - 1 is prime. %C A174352 The corresponding primes are in A145851. Primes found and proved by PrimeForm. No more terms up to 30000. %o A174352 (PARI) is(n)=ispseudoprime((n+1)*10^n-1) \\ _Charles R Greathouse IV_, May 22 2017 %Y A174352 Cf. A145851. %K A174352 nonn %O A174352 1,2 %A A174352 _Rick L. Shepherd_, Mar 22 2010