cp's OEIS Frontend

A345572 Numbers that are the sum of seven fourth powers in six or more ways.

%I A345572 #6 Jul 31 2021 17:58:05
%S A345572 10787,15396,15411,15586,15651,16611,16626,16676,16691,16866,17347,
%T A345572 17956,17971,18867,19156,19236,19251,19411,19426,19491,19666,20035,
%U A345572 20706,20771,21012,21187,21252,21267,21332,21397,21412,21442,21492,21507,21572,21621,21636
%N A345572 Numbers that are the sum of seven fourth powers in six or more ways.
%H A345572 Sean A. Irvine, <a href="/A345572/b345572.txt">Table of n, a(n) for n = 1..10000</a>
%e A345572 15396 is a term because 15396 = 1^4 + 1^4 + 1^4 + 1^4 + 6^4 + 8^4 + 10^4 = 1^4 + 1^4 + 2^4 + 5^4 + 8^4 + 8^4 + 9^4 = 1^4 + 2^4 + 2^4 + 2^4 + 3^4 + 5^4 + 11^4 = 1^4 + 3^4 + 4^4 + 4^4 + 7^4 + 7^4 + 10^4 = 1^4 + 3^4 + 5^4 + 7^4 + 8^4 + 8^4 + 8^4 = 2^4 + 3^4 + 4^4 + 5^4 + 6^4 + 9^4 + 9^4.
%o A345572 (Python)
%o A345572 from itertools import combinations_with_replacement as cwr
%o A345572 from collections import defaultdict
%o A345572 keep = defaultdict(lambda: 0)
%o A345572 power_terms = [x**4 for x in range(1, 1000)]
%o A345572 for pos in cwr(power_terms, 7):
%o A345572     tot = sum(pos)
%o A345572     keep[tot] += 1
%o A345572     rets = sorted([k for k, v in keep.items() if v >= 6])
%o A345572     for x in range(len(rets)):
%o A345572         print(rets[x])
%Y A345572 Cf. A345524, A345563, A345571, A345573, A345581, A345609, A345828.
%K A345572 nonn
%O A345572 1,1
%A A345572 _David Consiglio, Jr._, Jun 20 2021