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A345844
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Numbers that are the sum of nine fourth powers in exactly two ways.
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8
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264, 279, 294, 309, 324, 339, 344, 359, 374, 389, 404, 424, 439, 454, 469, 504, 549, 564, 579, 584, 614, 629, 644, 664, 679, 694, 709, 759, 789, 804, 819, 839, 854, 869, 884, 888, 903, 918, 933, 934, 948, 949, 968, 983, 998, 1013, 1014, 1029, 1044, 1048, 1059
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OFFSET
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1,1
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COMMENTS
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Differs from A345586 at term 17 because 519 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 4^4 + 4^4 = 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 3^4 + 3^4 + 3^4 + 4^4 = 1^4 + 2^4 + 2^4 + 3^4 + 3^4 + 3^4 + 3^4 + 3^4 + 3^4.
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LINKS
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Sean A. Irvine, Table of n, a(n) for n = 1..10000
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EXAMPLE
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279 is a term because 279 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 4^4 = 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 2^4 + 3^4 + 3^4 + 3^4.
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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, 9):
tot = sum(pos)
keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v == 2])
for x in range(len(rets)):
print(rets[x])
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CROSSREFS
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Cf. A345586, A345794, A345834, A345843, A345845, A345854, A346337.
Sequence in context: A157828 A065570 A345586 * A253694 A253701 A255804
Adjacent sequences: A345841 A345842 A345843 * A345845 A345846 A345847
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KEYWORD
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nonn
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AUTHOR
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David Consiglio, Jr., Jun 26 2021
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STATUS
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approved
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