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A345621 Numbers that are the sum of nine fifth powers in four or more ways.

%I A345621 #6 Jul 31 2021 16:09:02
%S A345621 55542,120350,143507,167241,182549,192233,202890,326685,327986,328247,
%T A345621 329028,329809,333257,351722,358474,358968,359210,359538,359813,
%U A345621 365404,367071,367313,374034,374846,375627,376619,377158,379259,381157,383910,384765,390396
%N A345621 Numbers that are the sum of nine fifth powers in four or more ways.
%H A345621 Sean A. Irvine, <a href="/A345621/b345621.txt">Table of n, a(n) for n = 1..10000</a>
%e A345621 120350 is a term because 120350 = 1^5 + 3^5 + 4^5 + 5^5 + 7^5 + 7^5 + 7^5 + 8^5 + 8^5 = 1^5 + 3^5 + 5^5 + 5^5 + 6^5 + 6^5 + 8^5 + 8^5 + 8^5 = 2^5 + 4^5 + 4^5 + 4^5 + 6^5 + 7^5 + 7^5 + 7^5 + 9^5 = 2^5 + 4^5 + 4^5 + 5^5 + 6^5 + 6^5 + 6^5 + 8^5 + 9^5.
%o A345621 (Python)
%o A345621 from itertools import combinations_with_replacement as cwr
%o A345621 from collections import defaultdict
%o A345621 keep = defaultdict(lambda: 0)
%o A345621 power_terms = [x**5 for x in range(1, 1000)]
%o A345621 for pos in cwr(power_terms, 9):
%o A345621     tot = sum(pos)
%o A345621     keep[tot] += 1
%o A345621     rets = sorted([k for k, v in keep.items() if v >= 4])
%o A345621     for x in range(len(rets)):
%o A345621         print(rets[x])
%Y A345621 Cf. A345588, A345612, A345620, A345622, A345636, A346339.
%K A345621 nonn
%O A345621 1,1
%A A345621 _David Consiglio, Jr._, Jun 20 2021