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A304286
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Sequence gives the denominators, in increasing values, of Egyptian fractions whose sum has the concatenation of these denominators as decimal part. Case a(1) = 4.
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20
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OFFSET
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1,1
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COMMENTS
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There are only three possible sequences of this kind: one starting from 3 (A302932), another from 4 (this sequence) and another from 10 (A302933).
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LINKS
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EXAMPLE
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We start from 4: 1/4 = 0.25. At the beginning we have 2 instead of 4 as first decimal digit but the second term will fix it.
In fact the next integer is 5 and 1/4 + 1/5 = 0.45 and so on.
The sum is 0.4 5 316 617610 803725588973 ...
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MAPLE
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P:=proc(q) local a, b, d, n; a:=1/4; b:=ilog10(1/a)+1; d:=1/a; print(d);
for n from 1 to q do if trunc(evalf(a+1/n, 100)*10^(b+ilog10(n)+1))=d*10^(ilog10(n)+1)+n then b:=b+ilog10(n)+1; d:=d*10^(ilog10(n)+1)+n; a:=a+1/n; print(n); fi; od; end: P(10^20);
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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