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A093099 "Fibonacci-digits": start with "11", append sum of first 2 digits to the preceding number, drop first digit.

%I A093099 #17 May 21 2020 20:36:26
%S A093099 11,12,23,35,58,813,139,394,9412,41213,12135,21353,13533,35334,53348,
%T A093099 33488,34886,48867,886712,8671216,67121614,712161413,121614138,
%U A093099 216141383,161413833,614138337,141383377,413833775,138337755,383377554,8337755411,33775541111
%N A093099 "Fibonacci-digits": start with "11", append sum of first 2 digits to the preceding number, drop first digit.
%H A093099 Robert Israel, <a href="/A093099/b093099.txt">Table of n, a(n) for n = 1..3793</a>
%e A093099 a(6): sum of first 2 digits of a(5)=13, append 13 to 58 and get 5813, drop first digit and get 813.
%p A093099 f:= proc(x) local t,q;
%p A093099   t:= floor(x/10^(ilog10(x)-1));
%p A093099   t:= (t mod 10) + floor(t/10);
%p A093099   t:= t+x*10^(ilog10(t)+1);
%p A093099   q:= 10^ilog10(t);
%p A093099   t - floor(t/q)*q
%p A093099 end proc:x:= 11: R:= x:
%p A093099 for n from 2 to 100 do x:= f(x); R:= R,x od:R; # _Robert Israel_, May 21 2020
%p A093099 # second Maple program:
%p A093099 a:= proc(n) option remember; `if`(n=1, 11, (s->parse(cat(
%p A093099       s[2..-1], parse(s[1])+parse(s[2]))))(""||(a(n-1))))
%p A093099     end:
%p A093099 seq(a(n), n=1..35);  # _Alois P. Heinz_, May 21 2020
%t A093099 fd[n_]:=Module[{idn=IntegerDigits[n]},FromDigits[Rest[Join[idn,IntegerDigits[Total[Take[idn,2]]]]]]]
%t A093099 NestList[fd,11,30]  (* _Harvey P. Dale_, Mar 06 2011 *)
%Y A093099 Cf. A093086-A093092.
%K A093099 nonn,base
%O A093099 1,1
%A A093099 _Bodo Zinser_, Mar 22 2004