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A085071 Integers reached in A085068.

%I A085071 #17 Feb 17 2023 07:38:44
%S A085071 0,4,4,4,8,84,8,84,20,12,84,20,16,24,84,20,40,56,24,84,36,28,40,56,32,
%T A085071 148,84,36,68,52,40,56,104,44,148,84,48,120,68,52,72,132,56,104,452,
%U A085071 60,148,84,64,88,120,68,168,404,72,132,100,76,104,452,80,196,148,84,872,116,88
%N A085071 Integers reached in A085068.
%H A085071 J. C. Lagarias and N. J. A. Sloane, Approximate squaring (<a href="http://neilsloane.com/doc/apsq.pdf">pdf</a>, <a href="http://neilsloane.com/doc/apsq.ps">ps</a>), Experimental Math., 13 (2004), 113-128.
%p A085071 a:= proc(n) local i; n; for i do 4/3*ceil(%);
%p A085071       if %::integer then return % fi od
%p A085071     end:
%p A085071 seq(a(n), n=0..100);  # _Alois P. Heinz_, Mar 01 2021
%t A085071 a[n_] := Module[{k = 4n/3}, While[!IntegerQ[k], k = 4* Ceiling[k]/3]; k];
%t A085071 Table[a[n], {n, 0, 100}] (* _Jean-François Alcover_, Feb 17 2023 *)
%o A085071 (Python3)
%o A085071 from fractions import Fraction
%o A085071 def A085071(n):
%o A085071     c, x = 0, Fraction(n,1)
%o A085071     while x.denominator > 1 or x <= n:
%o A085071         x = Fraction(4*x.__ceil__(),3)
%o A085071         c += 1
%o A085071     return x.numerator # _Chai Wah Wu_, Mar 01 2021
%K A085071 nonn
%O A085071 0,2
%A A085071 _N. J. A. Sloane_, Aug 11 2003