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 A147521 #7 Jan 12 2019 12:59:53
%S A147521 41,1681,2963603,19477970573,203586339651833,2677331022258108347,
%T A147521 40785586686127252393,3817838920923578492820563,
%U A147521 22427952844519540079208409331,3292526219739666997778171798741,59254464597252454704406353071130683,93363909561408736238900593787191180421
%N A147521 a(n) is the smallest value of Euler polynomial x^2 + x + 41 which is divisible by 41^n.
%C A147521 For values x see A147520 For values (x^2 + x + 41)/(41^n) see A147522.
%t A147521 a = {}; Do[x = 0; While[Mod[x^2 + x + 41, 41^n] != 0, x++ ]; AppendTo[a,x^2 + x + 41];Print[{n, x, x^2 + x + 41, (x^2 + x + 41)/41^n}], {n, 1, 6}];a
%Y A147521 Cf. A145292, A145293, A145294, A147520, A147521, A147522.
%K A147521 nonn
%O A147521 1,1
%A A147521 _Artur Jasinski_, Nov 06 2008
%E A147521 a(7)-a(12) from _Hugo Pfoertner_, Jan 12 2019