A379869 a(n) is the least number whose cube is an n-digit cube which has the maximum sum of digits (A373727(n)).

2, 4, 9, 19, 31, 92, 157, 423, 927, 1966, 4289, 8782, 12599, 30355, 99829, 215083, 341075, 989353, 2131842, 4081435, 8334082, 20632999, 43967926, 88316866, 190349299, 365830423, 735501679, 1948602829, 3036548692, 9654499999, 17087193298, 31037622999, 99594689449, 181610950229, 462575139319, 956829383603

Offset

1,1

Links

Table of n, a(n) for n=1..36.

Example

a(7) = 157 because among all 7-digit cubes, 157^3=3869893 is the smallest cube (another 2 larger cubes are 199^3=7880599, 208^3=8998912) who has the maximum sum of digits, 46 = A373727(7).

Mathematica

Table[t =SortBy[Map[{#, Total@IntegerDigits[#^3]} &,
    Range[Ceiling@CubeRoot[10^(n - 1)], CubeRoot[10^n - 1]]], Last];
 Select[t, #[[2]] == t[[-1]][[2]] &][[1, 1]], {n, 18}]

Crossrefs

Cf. A348303, A370522, A373727, A380052.

Sequence in context: A283877 A331850 A373808 * A081490 A292478 A309267

Adjacent sequences: A379866 A379867 A379868 * A379870 A379871 A379872

Keyword

nonn,base

Author

Zhining Yang, Jan 11 2025

Status

approved