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A047714
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Sums of 3 but no fewer nonzero fourth powers.
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5
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3, 18, 33, 48, 83, 98, 113, 163, 178, 243, 258, 273, 288, 338, 353, 418, 513, 528, 593, 627, 642, 657, 707, 722, 768, 787, 882, 897, 962, 1137, 1251, 1266, 1298, 1313, 1328, 1331, 1378, 1393, 1458, 1506, 1553, 1568, 1633, 1808, 1875, 1922, 1937, 2002, 2177
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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MAPLE
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N:= 3000: # for terms <= N
F1:= {seq(i^4, i=1..floor(N^(1/4)))}: n1:= nops(F1):
F2:= select(`<=`, {seq(seq(F1[i]+F1[j], i=1..j), j=1..nops(F1))}, N):
F3:= select(`<=`, {seq(seq(s+t, s=F1), t=F2)}, N):
A:= sort(convert(F3 minus (F2 union F1), list)); # Robert Israel, Jul 24 2020
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PROG
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(Python)
def aupto(lim):
p1 = set(i**4 for i in range(1, int(lim**.25)+2) if i**4 <= lim)
p2 = set(a+b for a in p1 for b in p1 if a+b <= lim)
p3 = set(apb+c for apb in p2 for c in p1 if apb+c <= lim)
return sorted(p3-p2-p1)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Arlin Anderson (starship1(AT)gmail.com)
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STATUS
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approved
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