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A003340
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Numbers that are the sum of 6 positive 4th powers.
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39
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6, 21, 36, 51, 66, 81, 86, 96, 101, 116, 131, 146, 161, 166, 181, 196, 211, 226, 246, 261, 276, 291, 306, 321, 326, 336, 341, 356, 371, 386, 401, 406, 421, 436, 451, 466, 486, 501, 516, 531, 546, 561, 576, 581, 596, 611, 626, 630, 641, 645, 660, 661, 675, 676, 690
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refs;
listen;
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internal format)
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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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13090 is in the sequence as 13090 = 4^4 + 4^4 + 5^4 + 6^4 + 8^4 + 9^4.
17539 is in the sequence as 17539 = 2^4 + 3^4 + 4^4 + 5^4 + 9^4 + 10^4.
23732 is in the sequence as 23732 = 3^4 + 5^4 + 5^4 + 7^4 + 10^4 + 10^4. (End)
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MATHEMATICA
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Select[Range[1000], AnyTrue[PowersRepresentations[#, 6, 4], First[#]>0&]&] (* Jean-François Alcover, Jul 18 2017 *)
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PROG
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(Python)
from itertools import combinations_with_replacement as combs_with_rep
def aupto(limit):
qd = [k**4 for k in range(1, int(limit**.25)+2) if k**4 + 5 <= limit]
ss = set(sum(c) for c in combs_with_rep(qd, 6))
return sorted(s for s in ss if s <= limit)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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