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 A130003 #11 Jul 18 2021 04:27:27 %S A130003 1,1,3,7,7,15,37,163,177,4503,4503,4503,4503,4503,833021343, %T A130003 12465115083,95854279610863,1158174141556287 %N A130003 a(n) is the smallest positive integer m such that 4^k + m is prime for all k=1,2,...,n. %H A130003 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_403.htm">Puzzle 403. 833021343</a>, The Prime Puzzles and Problems Connection. %e A130003 a(14)=4503 because 4^k + 4503 is prime for each k in 1..14 and there is no smaller number with this property. %Y A130003 Cf. A110096. %K A130003 nonn,hard,more %O A130003 1,3 %A A130003 _Farideh Firoozbakht_, May 30 2007, Jun 04 2007 %E A130003 More terms from _Jens Kruse Andersen_, Jun 08 2007