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 A253188 #19 Mar 29 2015 04:39:24
%S A253188 1,1,1,1,2,3,4,4,5,6,7,8,9,10,10,11,12,13,14,15,16,17,17,18,19,20,21,
%T A253188 22,23,24,25,26,26,27,28,29,30,31,32,33,34,35,36,36,37,38,39,40,41,42,
%U A253188 43,44,45,46,47,48,49,49,50,51,52,53,54,55,56,57,58,59
%N A253188 Minimal positive integer k such that n^n >= (n-k)^(n+k).
%H A253188 Bui Quang Tuan, <a href="/A253188/b253188.txt">Table of n, a(n) for n = 1..1000</a>
%e A253188 a(4) = 1 because 4^4 = 256 > 243 = (4-1)^(4+1).
%e A253188 a(5) = 2 because 5^5 = 3125 > 2187 = (5-2)^(5+2) (but < 4096 = (5-1)^(5+1)).
%t A253188 f[n_] := Block[{k = 1}, While[n^n < (n - k)^(n + k), k++]; k]; Array[f, 120] (* _Michael De Vlieger_, Mar 24 2015 *)
%o A253188 (PARI) a(n) = {k = 1; npn = n^n; while(npn < (n-k)^(n+k), k++); k;} \\ _Michel Marcus_, Mar 24 2015
%K A253188 nonn
%O A253188 1,5
%A A253188 _Bui Quang Tuan_, Mar 24 2015