A343987 Numbers that are the sum of four positive cubes in five or more ways.
5105, 5131, 5616, 5859, 6435, 6883, 7777, 9315, 9737, 9793, 10017, 10250, 10458, 10936, 10962, 11000, 11060, 11088, 11592, 11664, 11781, 12168, 12229, 12285, 12320, 12385, 12392, 12411, 12707, 13104, 13384, 13734, 13832, 13904, 13923, 14112, 14183, 14239, 14581, 14833, 14896, 14904, 15176, 15561, 15596
Offset: 1
Keywords
Examples
5616 = 1^3 + 8^3 + 12^3 + 15^3 = 2^3 + 8^3 + 10^3 + 16^3 = 4^3 + 4^3 + 14^3 + 14^3 = 4^3 + 5^3 + 11^3 + 16^3 = 8^3 + 9^3 + 10^3 + 15^3 so 5616 is a term.
Links
- David Consiglio, Jr., Table of n, a(n) for n = 1..20000
Programs
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Python
from itertools import combinations_with_replacement as cwr from collections import defaultdict keep = defaultdict(lambda: 0) power_terms = [x ** 3 for x in range(1, 50)] for pos in cwr(power_terms, 4): tot = sum(pos) keep[tot] += 1 rets = sorted([k for k, v in keep.items() if v >= 5]) for x in range(len(rets)): print(rets[x], end=", ")
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