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A084471 Change 0 to 00 in binary representation of n.

%I A084471 #23 Jan 29 2021 15:11:09
%S A084471 1,4,3,16,9,12,7,64,33,36,19,48,25,28,15,256,129,132,67,144,73,76,39,
%T A084471 192,97,100,51,112,57,60,31,1024,513,516,259,528,265,268,135,576,289,
%U A084471 292,147,304,153,156,79,768,385,388,195,400,201,204,103,448,225
%N A084471 Change 0 to 00 in binary representation of n.
%C A084471 a(n) = n iff n = 2^k - 1, k>0.
%C A084471 A023416(a(n))=A023416(n)*2; A000120(a(n))=A000120(n);
%H A084471 Reinhard Zumkeller, <a href="/A084471/b084471.txt">Table of n, a(n) for n = 1..10000</a>
%F A084471 a(1)=1, a(2*k+1)=2*a(k)+1, a(2*k)=4*a(k).
%p A084471 a:= n-> Bits[Join](subs(0=[0$2][], Bits[Split](n))):
%p A084471 seq(a(n), n=1..60);  # _Alois P. Heinz_, Jan 15 2021
%t A084471 f[n_] := FromDigits[Flatten[IntegerDigits[n, 2] /. {0 -> {0, 0}}], 2]; Array[f, 60] (* _Robert G. Wilson v_, Dec 10 2009 *)
%o A084471 (Haskell)
%o A084471 a084471 1 = 1
%o A084471 a084471 x = 2 * (2 - d) * a084471 x' + d  where (x',d) = divMod x 2
%o A084471 -- _Reinhard Zumkeller_, Jul 16 2012
%Y A084471 Cf. A084472(n)=A007088(a(n)), A084473, A038573.
%Y A084471 Ordered terms are in A060142.
%Y A084471 Column k=2 of A340666.
%Y A084471 Cf. A088698, A175047. - _Robert G. Wilson v_, Dec 10 2009
%K A084471 nonn,look,base
%O A084471 1,2
%A A084471 _Reinhard Zumkeller_, May 27 2003