cp's OEIS Frontend

A345842 Numbers that are the sum of eight fourth powers in exactly ten ways.

%I A345842 #6 Jul 31 2021 21:33:55
%S A345842 17972,17987,19492,19507,19747,20116,21283,21333,21413,21508,21588,
%T A345842 22067,22563,23237,23252,23587,23588,23603,23653,24277,24452,24802,
%U A345842 24948,25603,26228,27347,27683,27813,27893,27973,28532,28852,28853,28933,29108,29173,29491
%N A345842 Numbers that are the sum of eight fourth powers in exactly ten ways.
%C A345842 Differs from A345585 at term 7 because 20787 = 1^4 + 1^4 + 1^4 + 6^4 + 6^4 + 8^4 + 8^4 + 10^4  = 1^4 + 2^4 + 2^4 + 2^4 + 3^4 + 8^4 + 9^4 + 10^4  = 1^4 + 2^4 + 4^4 + 4^4 + 6^4 + 7^4 + 9^4 + 10^4  = 1^4 + 2^4 + 5^4 + 6^4 + 8^4 + 8^4 + 8^4 + 9^4  = 1^4 + 3^4 + 4^4 + 6^4 + 6^4 + 6^4 + 9^4 + 10^4  = 2^4 + 2^4 + 2^4 + 3^4 + 5^4 + 6^4 + 8^4 + 11^4  = 2^4 + 2^4 + 3^4 + 3^4 + 7^4 + 8^4 + 8^4 + 10^4  = 2^4 + 4^4 + 4^4 + 5^4 + 6^4 + 6^4 + 7^4 + 11^4  = 3^4 + 4^4 + 4^4 + 6^4 + 7^4 + 7^4 + 8^4 + 10^4  = 3^4 + 4^4 + 5^4 + 6^4 + 6^4 + 6^4 + 6^4 + 11^4  = 3^4 + 5^4 + 6^4 + 7^4 + 8^4 + 8^4 + 8^4 + 8^4.
%H A345842 Sean A. Irvine, <a href="/A345842/b345842.txt">Table of n, a(n) for n = 1..10000</a>
%e A345842 17987 is a term because 17987 = 1^4 + 1^4 + 1^4 + 6^4 + 6^4 + 6^4 + 8^4 + 10^4 = 1^4 + 2^4 + 2^4 + 2^4 + 3^4 + 6^4 + 9^4 + 10^4 = 1^4 + 2^4 + 5^4 + 6^4 + 6^4 + 8^4 + 8^4 + 9^4 = 2^4 + 2^4 + 2^4 + 2^4 + 4^4 + 5^4 + 7^4 + 11^4 = 2^4 + 2^4 + 2^4 + 3^4 + 5^4 + 6^4 + 6^4 + 11^4 = 2^4 + 2^4 + 3^4 + 3^4 + 6^4 + 7^4 + 8^4 + 10^4 = 2^4 + 4^4 + 4^4 + 4^4 + 7^4 + 7^4 + 7^4 + 10^4 = 2^4 + 4^4 + 5^4 + 7^4 + 7^4 + 8^4 + 8^4 + 8^4 = 3^4 + 4^4 + 4^4 + 6^4 + 6^4 + 7^4 + 7^4 + 10^4 = 3^4 + 5^4 + 6^4 + 6^4 + 7^4 + 8^4 + 8^4 + 8^4.
%o A345842 (Python)
%o A345842 from itertools import combinations_with_replacement as cwr
%o A345842 from collections import defaultdict
%o A345842 keep = defaultdict(lambda: 0)
%o A345842 power_terms = [x**4 for x in range(1, 1000)]
%o A345842 for pos in cwr(power_terms, 8):
%o A345842     tot = sum(pos)
%o A345842     keep[tot] += 1
%o A345842     rets = sorted([k for k, v in keep.items() if v == 10])
%o A345842     for x in range(len(rets)):
%o A345842         print(rets[x])
%Y A345842 Cf. A345585, A345792, A345832, A345841, A345852, A346335.
%K A345842 nonn
%O A345842 1,1
%A A345842 _David Consiglio, Jr._, Jun 26 2021