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 A380566 #25 Feb 01 2025 23:18:28
%S A380566 1,2,3,6,9,15,18,37,58,93,156,179,368,579,756,1379,2337,3965,6006,
%T A380566 9746,14198,25046,38779,60006,98746,151446,231755,389658,585516,
%U A380566 819199,1584779,2452779,3897999,5400759,9744998,15517759,23936959,28737498,62943519,95635199,156373159,225142779,351816939,595519999
%N A380566 a(n) = k is the largest k for which k^5 is n digits long and the sum of digits of k^5 is the maximum for any n digit 5th power (A374025).
%H A380566 Zhining Yang, <a href="/A380566/b380566.txt">Table of n, a(n) for n = 1..52</a>
%e A380566 a(14) = 579 because among all 14-digit fifth powers(399^5-630^5), 549^5=49872566977749,579^5=65071799758899, both have the maximum sum of digits, 90 = A374025(14) and 579 is the largest.
%t A380566 a[n_]:=Module[{m=Floor[(10^n-1)^(1/5)],max=0},For[k=m,k>=Ceiling[10^((n-1)/5)],k--,t=Total@IntegerDigits[k^5];If[t>max,s=k;max=t]];s];Table[a[n],{n,30}]
%Y A380566 Cf. A374025, A379650.
%Y A380566 Cf. A380052, A380193.
%K A380566 nonn,base
%O A380566 1,2
%A A380566 _Zhining Yang_, Jan 26 2025