cp's OEIS Frontend

A345766 Numbers that are the sum of six cubes in exactly four ways.

%I A345766 #7 Jul 31 2021 22:49:46
%S A345766 626,830,837,856,873,891,947,954,982,1008,1026,1052,1053,1071,1094,
%T A345766 1097,1106,1109,1134,1143,1150,1153,1172,1195,1208,1227,1234,1253,
%U A345766 1267,1278,1279,1283,1286,1290,1297,1316,1323,1324,1358,1361,1368,1369,1376,1395,1403
%N A345766 Numbers that are the sum of six cubes in exactly four ways.
%C A345766 Differs from A345513 at term 12 because 1045 = 1^3 + 1^3 + 2^3 + 2^3 + 3^3 + 10^3  = 1^3 + 1^3 + 4^3 + 5^3 + 5^3 + 9^3  = 1^3 + 2^3 + 3^3 + 4^3 + 6^3 + 9^3  = 3^3 + 3^3 + 6^3 + 6^3 + 6^3 + 7^3  = 4^3 + 4^3 + 4^3 + 5^3 + 6^3 + 8^3.
%H A345766 Sean A. Irvine, <a href="/A345766/b345766.txt">Table of n, a(n) for n = 1..1211</a>
%e A345766 830 is a term because 830 = 1^3 + 1^3 + 2^3 + 3^3 + 3^3 + 8^3 = 1^3 + 3^3 + 3^3 + 5^3 + 5^3 + 6^3 = 1^3 + 3^3 + 3^3 + 3^3 + 4^3 + 7^3 = 2^3 + 2^3 + 3^3 + 3^3 + 6^3 + 6^3.
%o A345766 (Python)
%o A345766 from itertools import combinations_with_replacement as cwr
%o A345766 from collections import defaultdict
%o A345766 keep = defaultdict(lambda: 0)
%o A345766 power_terms = [x**3 for x in range(1, 1000)]
%o A345766 for pos in cwr(power_terms, 6):
%o A345766     tot = sum(pos)
%o A345766     keep[tot] += 1
%o A345766     rets = sorted([k for k, v in keep.items() if v == 4])
%o A345766     for x in range(len(rets)):
%o A345766         print(rets[x])
%Y A345766 Cf. A048931, A344035, A345513, A345767, A345776, A345816.
%K A345766 nonn
%O A345766 1,1
%A A345766 _David Consiglio, Jr._, Jun 26 2021