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 A212290 #6 Jul 10 2015 20:13:17 %S A212290 9,255,1239,5895,221961 %N A212290 Difference between the smallest 10^n-bit prime and 2^(10^n-1). %C A212290 a(5) found by _Serge Batalov_, Jun 11 2012. %H A212290 Henri Lifchitz, Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/prptop.php">Probable Primes Top 10000.</a> %e A212290 2^99+255 is the smallest 100-bit prime, 2^999+1239 is the smallest 1000-bit prime, etc. %o A212290 (PARI) a(n)=nextprime(2^(10^n-1))-2^(10^n-1) %Y A212290 Binary analog of A096548. %K A212290 nonn,hard %O A212290 1,1 %A A212290 _Charles R Greathouse IV_, Jun 16 2012