A380111 a(n) is the least number whose fourth power is an n-digit fourth power which has the maximum sum of digits (A373914(n)).

1, 3, 4, 8, 16, 26, 47, 74, 118, 308, 518, 659, 1768, 2868, 5396, 8256, 14482, 28871, 55368, 97063, 147768, 228558, 562341, 835718, 1727156, 2878406, 5458722, 8175708, 16234882, 27831542, 53129506, 98665756, 166025442, 315265896, 510466356, 904245732, 1188893858, 2298249374, 5106312756

Offset: 1

Author

Zhining Yang, Jan 12 2025

Keywords

• nonn
• base

Examples

			a(7) = 47 because among all 7-digit fourth powers, 47^4=487968 is the least one (another larger is 56^4=9834496) which has the maximum sum of digits, 43 = A373914(7).
		

Links

• Zhining Yang, Table of n, a(n) for n = 1..49 [a(42) and a(49) corrected by _Kevin Ryde_, Mar 29 2025]

Crossrefs

Cf. A373914, A380797.

Other powers: A379869, A379650, A380567.

Programs

C

/* See A373914. */

Mathematica

Table[t=SortBy[Map[{#,Total@IntegerDigits[#^4]}&,Range[Ceiling[10^((n-1)/4)],Floor[(10^n-1)^(1/4)]]],Last];
Select[t,#[[2]]==t[[-1]][[2]]&][[1,1]],{n,24}]