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A003370 Numbers that are the sum of 3 positive 7th powers. 32

%I #18 Aug 04 2020 17:16:36

%S 3,130,257,384,2189,2316,2443,4375,4502,6561,16386,16513,16640,18572,

%T 18699,20758,32769,32896,34955,49152,78127,78254,78381,80313,80440,

%U 82499,94510,94637,96696,110893,156251,156378,158437,172634,234375,279938,280065,280192,282124,282251

%N Numbers that are the sum of 3 positive 7th powers.

%H Chai Wah Wu, <a href="/A003370/b003370.txt">Table of n, a(n) for n = 1..10000</a>

%e From _David A. Corneth_, Aug 04 2020: (Start)

%e 1320614777 is in the sequence as 1320614777 = 9^7 + 12^7 + 20^7.

%e 5868568576 is in the sequence as 5868568576 = 8^7 + 20^7 + 24^7.

%e 17285710304 is in the sequence as 17285710304 = 3^7 + 12^7 + 29^7. (End)

%o (PARI) list(lim)=my(v=List(),x7,t); lim\=1; for(x=1,sqrtnint(lim-2,7), x7=x^7; for(y=1,min(sqrtnint(lim-x7,7),x), t=x7+y^7; for(z=1,min(sqrtnint(lim-t,7),y), listput(v,t+z^7)))); Set(v) \\ _Charles R Greathouse IV_, Nov 05 2017

%Y Cf. A001015.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_

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Last modified March 28 08:22 EDT 2024. Contains 371236 sequences. (Running on oeis4.)