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Equal Sums of Like Powers $(11.1.n)$ for $10\le n \le 19$.

数论 Math StackExchange 2 票 1 回答 66 浏览 提问者: Mrexcel 2026-07-05 15:28
number-theory diophantine-equations

问题内容

Suppose $a(n)$ is the minimum integer $k$ such that $k^{11}$ can be expressed as the sum of $n$ distinct positive 11th powers.

Q: Find $a(n)$ for $10\le n\le 19$.

For example, $a(20)=119$ because $199^{11}$ is the sum of 20 terms of $11$th powers,

$119^{11}=118^{11}+90^{11}+81^{11}+80^{11}+76^{11}+72^{11}+69^{11}+63^{11}+56^{11}+53^{11}+52^{11}+46^{11}+41^{11}+38^{11}+35^{11}+26^{11}+23^{11}+13^{11}+6^{11}+5^{11}$

$a(121)=204$ because $204^{11}$ is the sum of 121 terms of $11$th powers,

$204^{11}=161^{11}+160^{11}+159^{11}+158^{11}+157^{11}+156^{11}+155^{11}+154^{11}+153^{11}+152^{11}+151^{11}+150^{11}+149^{11}+147^{11}+146^{11}+145^{11}+144^{11}+143^{11}+142^{11}+141^{11}+140^{11}+139^{11}+138^{11}+137^{11}+136^{11}+135^{11}+134^{11}+133^{11}+132^{11}+131^{11}+130^{11}+129^{11}+128^{11}+127^{11}+126^{11}+125^{11}+124^{11}+123^{11}+122^{11}+121^{11}+120^{11}+119^{11}+118^{11}+117^{11}+116^{11}+115^{11}+114^{11}+113^{11}+112^{11}+111^{11}+110^{11}+109^{11}+108^{11}+107^{11}+106^{11}+104^{11}+103^{11}+102^{11}+101^{11}+100^{11}+99^{11}+98^{11}+97^{11}+96^{11}+95^{11}+94^{11}+93^{11}+92^{11}+91^{11}+90^{11}+89^{11}+88^{11}+87^{11}+86^{11}+84^{11}+83^{11}+82^{11}+81^{11}+80^{11}+79^{11}+78^{11}+77^{11}+76^{11}+75^{11}+74^{11}+73^{11}+71^{11}+70^{11}+69^{11}+68^{11}+67^{11}+66^{11}+65^{11}+60^{11}+59^{11}+49^{11}+44^{11}+41^{11}+39^{11}+31^{11}+28^{11}+27^{11}+25^{11}+23^{11}+22^{11}+21^{11}+18^{11}+17^{11}+16^{11}+14^{11}+13^{11}+11^{11}+10^{11}+9^{11}+8^{11}+7^{11}+6^{11}+5^{11}+3^{11}+2^{11}+1^{11}$

I have found all a(k) for $20\le n\le 101$.

Current progress:

a(10) >= 285
a(11) >= 232
a(12) >= 198
a(13) >= 171
a(14) >= 153
a(15) >= 301
a(16) >= 201
a(17) >= 133
a(18) >= 123
a(19) >= 116

See also: Equal Sums of Like Powers 11.1.n (An academic online discussion forum for the Mathematics Research Network)

回答 (1)

Tito Piezas III 2 票 2026-07-05 18:51 原文

The definitive place to go for numerical solutions is Jean-Charles Meyrignac's http://euler.free.fr/database.txt. Unfortunately, most doesn't seem to have been updated since 2005.

There are only two $(11,1,n)$ in the database. (Note: I didn't put the two in LaTex form for easier copy-paste.)


I. $(11,1,16)$ by Luigi Morelli in 1999 with $a(16) = 78$

78^11 = 71^11 + 69^11 + 66^11 + 64^11 + 63^11 + 52^11 + 47^11 + 43^11 + 29^11 + 23^11 + 23^11 + 22^11 + 14^11 + 12^11 + 7^11 + 1

II. $(11,1,15)$ by Jarek Wroblewski in 2003 with $a(15) = 249$

249^11 = 237^11 + 215^11 + 210^11 + 182^11 + 173^11 + 170^11 + 135^11 + 125^11 + 68^11 + 68^11 + 42^11 + 42^11 + 39^11 + 32^11 + 29^11 

Note: So your guess of $a(16) \ge 201$ and $a(15) \ge 301$ were too high.


III. There is a $(10,1,12)$ and $(9,1,10)$

1772^10 = 62^10 + 115^10 + 172^10 + 245^10 + 295^10 + 533^10 + 689^10 + 927^10 + 1011^10 + 1234^10 + 1603^10 + 1684^10

917^9 = 42^9 + 99^9 + 179^9 + 475^9 + 542^9 + 574^9 + 625^9 + 668^9 + 822^9 + 851^9

both by Wroblewski and these are the smallest known for now.