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 A216471 #20 Aug 27 2020 05:41:43
%S A216471 1,3,271,61535,50812751,21358519,237419801716063,1135029771535910655,
%T A216471 8972959412935210028959,91620671606331844031,
%U A216471 1599468651197092802422012477487,702649782312030280795815963215,978557919186290794806960014681034796687
%N A216471 Smallest k such that k*n^4 + 1 is an n-th power.
%e A216471 a(3) = 271 because 271*3^4 + 1 = 21952 = 28^3.
%t A216471 a={}; Do[k = 2; While[ !IntegerQ[(k^n - 1)/n^4], k++ ]; AppendTo[a, (k^n-1)/n^4], {n, 1, 20}]; a
%Y A216471 Cf. A076943, A193746, A216439.
%K A216471 nonn
%O A216471 1,2
%A A216471 _Michel Lagneau_, Sep 10 2012