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 A344643 Numbers that are the sum of five fifth powers in exactly one way. 6

%I

%S 5,36,67,98,129,160,247,278,309,340,371,489,520,551,582,731,762,793,

%T 973,1004,1028,1059,1090,1121,1152,1215,1270,1301,1332,1363,1512,1543,

%U 1574,1754,1785,1996,2051,2082,2113,2144,2293,2324,2355,2535,2566,2777,3074,3105,3129,3136,3160,3191,3222,3253,3316,3347,3371

%N Numbers that are the sum of five fifth powers in exactly one way.

%C Differs from A003350 at term 67 because 4097 = 1^5 + 4^5 + 4^5 + 4^5 + 4^5 = 3^5 + 3^5 + 3^5 + 3^5 + 6^5

%H David Consiglio, Jr., <a href="/A344643/b344643.txt">Table of n, a(n) for n = 1..20000</a>

%e 67 is a term because 67 = 1^5 + 1^5 + 1^5 + 2^5 + 2^5

%o (Python)

%o from itertools import combinations_with_replacement as cwr

%o from collections import defaultdict

%o keep = defaultdict(lambda: 0)

%o power_terms = [x**5 for x in range(1, 500)]

%o for pos in cwr(power_terms, 5):

%o tot = sum(pos)

%o keep[tot] += 1

%o rets = sorted([k for k, v in keep.items() if v == 1])

%o for x in range(len(rets)):

%o print(rets[x])

%Y Cf. A003350, A342686, A344190, A344642, A346356.

%K nonn

%O 1,1

%A _David Consiglio, Jr._, May 25 2021

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Last modified October 25 17:22 EDT 2021. Contains 348255 sequences. (Running on oeis4.)