cp's OEIS Frontend

A345559 Numbers that are the sum of six fourth powers in two or more ways.

%I A345559 #6 Jul 31 2021 18:04:58
%S A345559 261,276,291,341,356,421,516,531,596,771,885,900,965,1140,1361,1509,
%T A345559 1556,1571,1636,1811,2180,2596,2611,2661,2676,2691,2706,2721,2741,
%U A345559 2756,2771,2786,2836,2851,2916,2931,2946,2961,3011,3026,3091,3186,3201,3220,3266
%N A345559 Numbers that are the sum of six fourth powers in two or more ways.
%H A345559 Sean A. Irvine, <a href="/A345559/b345559.txt">Table of n, a(n) for n = 1..10000</a>
%e A345559 276 is a term because 276 = 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 4^4 = 1^4 + 2^4 + 2^4 + 3^4 + 3^4 + 3^4.
%o A345559 (Python)
%o A345559 from itertools import combinations_with_replacement as cwr
%o A345559 from collections import defaultdict
%o A345559 keep = defaultdict(lambda: 0)
%o A345559 power_terms = [x**4 for x in range(1, 1000)]
%o A345559 for pos in cwr(power_terms, 6):
%o A345559     tot = sum(pos)
%o A345559     keep[tot] += 1
%o A345559     rets = sorted([k for k, v in keep.items() if v >= 2])
%o A345559     for x in range(len(rets)):
%o A345559         print(rets[x])
%Y A345559 Cf. A003340, A344238, A345507, A345511, A345560, A345568, A345814.
%K A345559 nonn
%O A345559 1,1
%A A345559 _David Consiglio, Jr._, Jun 20 2021