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 A200046 #12 Mar 30 2012 18:36:00 %S A200046 15,25,33,35,39,55,57,69,75,95,99,115,117,119,121,123,125,129,135,143, %T A200046 145,153,155,169,175,195,203,205,209,215,217,221,225,235,247,253,255, %U A200046 259,273,275,285,289,295,299,305,309,315,319,321,323,325,333,335,339 %N A200046 Numbers n such that the equation x^n + (x+1)^n = (x+2)^n (mod n), x = 0..n-1 has no solution. %C A200046 All numbers are composites. %p A200046 for n from 1 to 340 do:ii:=0:for x from 0 to n-1 do:if x^n+(x+1)^n -(x+2)^n mod n =0 then ii:=ii+1:else fi:od: if ii=0 then printf(`%d, `,n):else fi:od: %Y A200046 Cf. A195637, A200219. %K A200046 nonn %O A200046 1,1 %A A200046 _Michel Lagneau_, Nov 14 2011