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A072723
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Integers which are exactly the concatenation of the first m odd numbers (A019519) divided by their sum (A000290 = m^2).
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3
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OFFSET
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1,2
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COMMENTS
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A probability argument suggests that this sequence may be finite.
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LINKS
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EXAMPLE
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a(1) = 1/1 = 1; a(2) = 135/(1+3+5) = 15; a(3) = 1357911131517/(1+3+5+7+9+11+13+15+17) = 16764334957; a(4) = 1357911131517192123252729313335373941/(1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31+33+35+37+39+41) = 3079163563531047898532266016633501.
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MATHEMATICA
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Select[Table[FromDigits[Flatten[IntegerDigits/@Range[1, 2n+1, 2]]]/Total[Range[1, 2n+1, 2]], {n, 0, 30}], IntegerQ] (* Harvey P. Dale, Mar 24 2023 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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