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 A030531 #5 Oct 01 2013 17:57:27 %S A030531 0,14,6300,19166,4766580,14316134,3485735820,10458256046, %T A030531 2541798719460,7625463267254,1853015893884540,5559051976620926, %U A030531 1350851442795085140,4052554603263162374,984770884591425188460,2954312671366461609806 %N A030531 Value of 3^x - 2^x - 5 for the solutions of 3^x - 2^x == 5 (mod 7). %D A030531 Emil Grosswald, Topics From the Theory of Numbers. 1966 p 65 problem 23 %o A030531 (PARI) f(n) = for(x=1,n,y=3^x-2^x-5; if(y%7==0,print1(y" "))) %Y A030531 Cf. A047243. %K A030531 nonn %O A030531 1,2 %A A030531 _Cino Hilliard_, May 09 2003