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A109867
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.
0
12, 297, 539055, 12949081200, 167631138529627443759, 888408727567955042239409874101472777521040, 787659989217062162749912989661115208857840881836480202901460330472578518132645989056
OFFSET
1,1
COMMENTS
The next term has 168 digits. - Harvey P. Dale, Dec 01 2017
EXAMPLE
a(2) = (12 + 21)*(21 - 12) = 297.
MATHEMATICA
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 *)
CROSSREFS
Sequence in context: A223011 A245915 A377631 * A326437 A303068 A014130
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jul 09 2005
EXTENSIONS
Corrected and extended by Stefan Steinerberger, Jun 05 2007
Definition corrected by Georg Fischer, Sep 09 2022
STATUS
approved