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A345572
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Numbers that are the sum of seven fourth powers in six or more ways.
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8
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10787, 15396, 15411, 15586, 15651, 16611, 16626, 16676, 16691, 16866, 17347, 17956, 17971, 18867, 19156, 19236, 19251, 19411, 19426, 19491, 19666, 20035, 20706, 20771, 21012, 21187, 21252, 21267, 21332, 21397, 21412, 21442, 21492, 21507, 21572, 21621, 21636
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OFFSET
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1,1
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LINKS
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EXAMPLE
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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.
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PROG
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(Python)
from itertools import combinations_with_replacement as cwr
from collections import defaultdict
keep = defaultdict(lambda: 0)
power_terms = [x**4 for x in range(1, 1000)]
for pos in cwr(power_terms, 7):
tot = sum(pos)
keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v >= 6])
for x in range(len(rets)):
print(rets[x])
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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