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A109867
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a(1) = 12; for n >= 1, a(n+1) = abs((a(n) + R(a(n))) * (a(n) - R(a(n)))), where R(k) is the digit reversal of k.
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0
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12, 297, 539055, 12949081200, 167631138529627443759, 888408727567955042239409874101472777521040, 787659989217062162749912989661115208857840881836480202901460330472578518132645989056
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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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EXAMPLE
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a(2) = (12 + 21)*(21 - 12) = 297.
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MATHEMATICA
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a = {12}; For[n = 2, n < 10, n++, AppendTo[a, Abs[(a[[ -1]] + FromDigits[Reverse[IntegerDigits[a[[ -1]]]]])* (a[[ -1]] - FromDigits[Reverse[IntegerDigits[a[[ -1]]]]])]]]; a (* Stefan Steinerberger, Jun 05 2007 *)
NestList[(#+IntegerReverse[#])Abs[#-IntegerReverse[#]]&, 12, 10] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 01 2017 *)
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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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EXTENSIONS
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STATUS
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approved
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