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 A171554 #9 Jun 30 2024 11:13:43 %S A171554 0,1,5,71,311 %N A171554 Numbers k such that 1 + 9*10^k + 100^k is prime. %C A171554 No more terms up to k = 7200. %C A171554 No more terms up to k = 27200. - _Michael S. Branicky_, Jun 30 2024 %t A171554 Select[Range[0,320],PrimeQ[1+9 10^#+100^#]&] (* _Harvey P. Dale_, Nov 23 2023 *) %o A171554 (PARI) is(n)=ispseudoprime(1+9*10^n+100^n) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A171554 Cf. A171376, A171411, A171459, A171514. %K A171554 more,nonn %O A171554 1,3 %A A171554 _Jason Earls_, Dec 11 2009