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 A380797 #15 Mar 29 2025 02:28:37
%S A380797 1,3,5,8,16,26,56,88,118,308,518,974,1768,2868,5396,8979,17306,28871,
%T A380797 55368,97063,167622,289146,562341,835718,1727156,3154276,5623116,
%U A380797 9397404,17728256,27831542,53129506,98665756,166025442,315265896,510466356,904245732,1188893858,2298249374,5315776056
%N A380797 a(n) is the largest number whose fourth power is an n-digit which has the maximum sum of digits (A373914(n)).
%e A380797 a(7) = 56 because among all 7-digit fourth powers, 56^4=9834496 is the largest one (another smaller is 47^4=487968) which has the maximum sum of digits, 43 = A373914(7).
%t A380797 a[n_]:=Module[{m=Floor[(10^n-1)^(1/4)], max=0},
%t A380797 For[k=m, k>=Ceiling[10^((n-1)/4)], k--, t=Total@IntegerDigits[k^4];
%t A380797 If[t>max, s=k; max=t]]; s];
%t A380797 Table[a[n], {n, 30}]
%o A380797 (C) /* See A373914. */
%Y A380797 Cf. A373914, A380111.
%Y A380797 Other powers: A379298, A380052, A380566, A380193.
%K A380797 nonn,base
%O A380797 1,2
%A A380797 _Zhining Yang_, Feb 03 2025