cp's OEIS Frontend

A344942 Numbers that are the sum of five fourth powers in seven or more ways.

%I A344942 #8 Jul 31 2021 18:13:33
%S A344942 197779,211059,217154,236675,431155,444019,480739,503539,530659,
%T A344942 534130,548994,564979,568450,571539,602450,602770,619090,621859,
%U A344942 625635,625939,626194,650659,651954,653059,654130,654754,663155,666739,687314,692754,692899,698019
%N A344942 Numbers that are the sum of five fourth powers in seven or more ways.
%H A344942 David Consiglio, Jr., <a href="/A344942/b344942.txt">Table of n, a(n) for n = 1..10000</a>
%e A344942 197779 is a term because 197779 = 1^4 + 5^4 + 6^4 + 16^4 + 19^4  = 1^4 + 7^4 + 11^4 + 12^4 + 20^4  = 1^4 + 10^4 + 12^4 + 17^4 + 17^4  = 2^4 + 4^4 + 5^4 + 7^4 + 21^4  = 3^4 + 5^4 + 6^4 + 6^4 + 21^4  = 4^4 + 7^4 + 9^4 + 13^4 + 20^4  = 11^4 + 13^4 + 14^4 + 15^4 + 16^4.
%o A344942 (Python)
%o A344942 from itertools import combinations_with_replacement as cwr
%o A344942 from collections import defaultdict
%o A344942 keep = defaultdict(lambda: 0)
%o A344942 power_terms = [x**4 for x in range(1, 1000)]
%o A344942 for pos in cwr(power_terms, 5):
%o A344942     tot = sum(pos)
%o A344942     keep[tot] += 1
%o A344942 rets = sorted([k for k, v in keep.items() if v >= 7])
%o A344942 for x in range(len(rets)):
%o A344942     print(rets[x])
%Y A344942 Cf. A344922, A344940, A344943, A344944, A345180, A345564.
%K A344942 nonn
%O A344942 1,1
%A A344942 _David Consiglio, Jr._, Jun 03 2021