cp's OEIS Frontend

A345560 Numbers that are the sum of six fourth powers in three or more ways.

%I A345560 #6 Jul 31 2021 18:05:01
%S A345560 2676,2851,2916,4131,4226,4241,4306,4371,4481,4850,5346,5411,5521,
%T A345560 5586,5651,6561,6611,6626,6691,6756,6771,6801,6821,6836,6851,6866,
%U A345560 6931,7106,7235,7475,7491,7666,7841,7906,7971,8146,8211,8321,8386,8451,8531,8706,9011
%N A345560 Numbers that are the sum of six fourth powers in three or more ways.
%H A345560 Sean A. Irvine, <a href="/A345560/b345560.txt">Table of n, a(n) for n = 1..10000</a>
%e A345560 2851 is a term because 2851 = 1^4 + 1^4 + 1^4 + 4^4 + 6^4 + 6^4 = 2^4 + 2^4 + 3^4 + 3^4 + 4^4 + 7^4 = 2^4 + 3^4 + 3^4 + 3^4 + 6^4 + 6^4.
%o A345560 (Python)
%o A345560 from itertools import combinations_with_replacement as cwr
%o A345560 from collections import defaultdict
%o A345560 keep = defaultdict(lambda: 0)
%o A345560 power_terms = [x**4 for x in range(1, 1000)]
%o A345560 for pos in cwr(power_terms, 6):
%o A345560     tot = sum(pos)
%o A345560     keep[tot] += 1
%o A345560     rets = sorted([k for k, v in keep.items() if v >= 3])
%o A345560     for x in range(len(rets)):
%o A345560         print(rets[x])
%Y A345560 Cf. A344243, A345512, A345559, A345561, A345569, A345604, A345815.
%K A345560 nonn
%O A345560 1,1
%A A345560 _David Consiglio, Jr._, Jun 20 2021