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A344922
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Numbers that are the sum of four fourth powers in seven or more ways.
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8
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6576339, 13155858, 16020018, 16408434, 22673634, 23056803, 26421474, 33734834, 35965458, 39786098, 39803778, 43583138, 51071619, 52652754, 53731458, 57976083, 63985314, 64365939, 67655779, 68846274, 73744563, 75951138, 77495778, 87038883, 88648914, 89148114
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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David Consiglio, Jr., Table of n, a(n) for n = 1..1000
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EXAMPLE
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6576339 is a term because 6576339 = 1^4 + 24^4 + 41^4 + 43^4 = 3^4 + 7^4 + 41^4 + 44^4 = 4^4 + 23^4 + 27^4 + 49^4 = 6^4 + 31^4 + 41^4 + 41^4 = 7^4 + 11^4 + 36^4 + 47^4 = 7^4 + 21^4 + 28^4 + 49^4 = 12^4 + 17^4 + 29^4 + 49^4.
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PROG
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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, 4):
tot = sum(pos)
keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v == 7])
for x in range(len(rets)):
print(rets[x])
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CROSSREFS
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Cf. A344729, A344904, A344923, A344924, A344942, A345150.
Sequence in context: A115615 A257016 A234090 * A344923 A204404 A266914
Adjacent sequences: A344919 A344920 A344921 * A344923 A344924 A344925
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KEYWORD
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nonn
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AUTHOR
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David Consiglio, Jr., Jun 02 2021
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STATUS
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approved
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