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 A067906 #15 Feb 14 2015 21:12:15 %S A067906 2,3,5,7,11,211,1009,3851,7523,9403,18367,213821,815663,2010764683, %T A067906 831632781251,23636425261531,537430088605367,7896825413969130677, %U A067906 226627774989027955951103,451298593966207394017315520293 %N A067906 Primes of the form floor((5/4)^k). %H A067906 Charles R Greathouse IV, <a href="/A067906/b067906.txt">Table of n, a(n) for n = 1..31</a> %t A067906 Union[Select[Floor[(5/4)^Range[0,400]],PrimeQ]] (* _Harvey P. Dale_, Jan 06 2012 *) %o A067906 (PARI) for(n=1,1e4, if(ispseudoprime(t=floor((5/4)^n)),print1(t", "))) \\ _Charles R Greathouse IV_, Feb 17 2011 %K A067906 nonn %O A067906 1,1 %A A067906 _Benoit Cloitre_, Mar 03 2002