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A131293 Concatenate a(n-2) and a(n-1) to get a(n); start with a(0)=0, a(1)=1, delete the leading zero. Also: concatenate Fibonacci(n) 1's.

%I A131293 #32 Sep 08 2022 08:45:31
%S A131293 0,1,1,11,111,11111,11111111,1111111111111,111111111111111111111,
%T A131293 1111111111111111111111111111111111,
%U A131293 1111111111111111111111111111111111111111111111111111111
%N A131293 Concatenate a(n-2) and a(n-1) to get a(n); start with a(0)=0, a(1)=1, delete the leading zero. Also: concatenate Fibonacci(n) 1's.
%C A131293 Interpreted as base-2 numbers the result is A063896.
%C A131293 This sequence differs from A108047 by the leading a(0) = 0. - _Jason Kimberley_, Dec 15 2012
%H A131293 Vincenzo Librandi, <a href="/A131293/b131293.txt">Table of n, a(n) for n = 0..18</a>
%F A131293 a(n) = a(n-2)*10^ceiling(log_10(a(n-1))) + a(n-1) for n > 1.
%F A131293 a(n) = (10^Fibonacci(n) - 1)/9.
%e A131293 a(3)=11, a(4)=111, so a(5) = a(4)*a(3) = 11111.
%p A131293 a:= n-> parse(cat(0, 1$combinat[fibonacci](n))):
%p A131293 seq(a(n), n=0..11);  # _Alois P. Heinz_, Apr 17 2020
%t A131293 Join[{0},FromDigits/@(PadLeft[{},#,1]&/@Fibonacci[Range[10]])] (* _Harvey P. Dale_, Aug 28 2011 *)
%o A131293 (Magma) [(10^Fibonacci(n)-1)/9: n in [0..10]]; // _Vincenzo Librandi_, Aug 29 2011
%o A131293 (Haskell)
%o A131293 import Data.Function (on)
%o A131293 a131293 n = a131293_list !! n
%o A131293 a131293_list = 0 : 1 : map read
%o A131293                (zipWith ((++) `on` show) a131293_list $ tail a131293_list)
%o A131293 -- _Reinhard Zumkeller_, Oct 05 2015
%Y A131293 Cf. A000045, A061107.
%Y A131293 Cf. A037842, A108047.
%K A131293 nonn,base
%O A131293 0,4
%A A131293 _Hieronymus Fischer_, Jun 26 2007