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 A109867 a(1) = 12; for n >= 1, a(n+1) = {a(n)+R(a(n)}*{a(n)-R(a(n)}, where R(k) is the digit reversal of k. 0

%I

%S 12,297,539055,12949081200,167631138529627443759,

%T 888408727567955042239409874101472777521040,

%U 787659989217062162749912989661115208857840881836480202901460330472578518132645989056

%N a(1) = 12; for n >= 1, a(n+1) = {a(n)+R(a(n)}*{a(n)-R(a(n)}, where R(k) is the digit reversal of k.

%C The next term has 168 digits. - _Harvey P. Dale_, Dec 01 2017

%e a(2) = (12 + 21)*(21 - 12) = 297.

%t 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 *)

%t NestList[(#+IntegerReverse[#])Abs[#-IntegerReverse[#]]&,12,10] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 01 2017 *)

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Jul 09 2005

%E Corrected and extended by _Stefan Steinerberger_, Jun 05 2007

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Last modified August 17 19:38 EDT 2022. Contains 356189 sequences. (Running on oeis4.)