A093099 - OEIS

%I #17 May 21 2020 20:36:26

%S 11,12,23,35,58,813,139,394,9412,41213,12135,21353,13533,35334,53348,

%T 33488,34886,48867,886712,8671216,67121614,712161413,121614138,

%U 216141383,161413833,614138337,141383377,413833775,138337755,383377554,8337755411,33775541111

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

%H Robert Israel, <a href="/A093099/b093099.txt">Table of n, a(n) for n = 1..3793</a>

%e 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 f:= proc(x) local t,q;

%p   t:= floor(x/10^(ilog10(x)-1));

%p   t:= (t mod 10) + floor(t/10);

%p   t:= t+x*10^(ilog10(t)+1);

%p   q:= 10^ilog10(t);

%p   t - floor(t/q)*q

%p end proc:x:= 11: R:= x:

%p for n from 2 to 100 do x:= f(x); R:= R,x od:R; # _Robert Israel_, May 21 2020

%p # second Maple program:

%p a:= proc(n) option remember; `if`(n=1, 11, (s->parse(cat(

%p       s[2..-1], parse(s[1])+parse(s[2]))))(""||(a(n-1))))

%p     end:

%p seq(a(n), n=1..35);  # _Alois P. Heinz_, May 21 2020

%t fd[n_]:=Module[{idn=IntegerDigits[n]},FromDigits[Rest[Join[idn,IntegerDigits[Total[Take[idn,2]]]]]]]

%t NestList[fd,11,30]  (* _Harvey P. Dale_, Mar 06 2011 *)

%Y Cf. A093086-A093092.

%K nonn,base

%O 1,1

%A _Bodo Zinser_, Mar 22 2004