login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Numbers that are the sum of six fifth powers in nine or more ways.
6

%I #10 May 10 2024 02:41:51

%S 9085584992,16933805856,37377003050,39254220544,41066625600,

%T 41485873792,42149876800,43828403850,44180505600,45902654525,

%U 48588434400,52005184992,53536896864,54156285568,55302546200,56229189632,57088402525,59954496800,63432407850

%N Numbers that are the sum of six fifth powers in nine or more ways.

%H Sean A. Irvine, <a href="/A345723/b345723.txt">Table of n, a(n) for n = 1..127</a>

%e 16933805856 = 2^5 + 38^5 + 68^5 + 74^5 + 92^5 + 92^5

%e = 2^5 + 54^5 + 58^5 + 64^5 + 92^5 + 96^5

%e = 14^5 + 36^5 + 61^5 + 67^5 + 94^5 + 94^5

%e = 15^5 + 49^5 + 52^5 + 60^5 + 94^5 + 96^5

%e = 17^5 + 49^5 + 53^5 + 57^5 + 92^5 + 98^5

%e = 29^5 + 36^5 + 42^5 + 72^5 + 88^5 + 99^5

%e = 31^5 + 36^5 + 54^5 + 54^5 + 94^5 + 97^5

%e = 34^5 + 34^5 + 46^5 + 72^5 + 76^5 + 104^5

%e = 35^5 + 36^5 + 69^5 + 72^5 + 89^5 + 95^5

%e so 16933805856 is a term.

%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, 1000)]

%o for pos in cwr(power_terms, 6):

%o tot = sum(pos)

%o keep[tot] += 1

%o rets = sorted([k for k, v in keep.items() if v >= 9])

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

%o print(rets[x])

%Y Cf. A344196, A345566, A345631, A345722, A346364.

%K nonn

%O 1,1

%A _David Consiglio, Jr._, Jun 24 2021