%I A085058
%S A085058 2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,6,2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,7,2,3,2,
%T A085058 4,2,3,2,5,2,3,2,4,2,3,2,6,2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,8,2,3,2,4,2,3,
%U A085058 2,5,2,3,2,4,2,3,2,6,2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,7,2,3,2,4,2,3,2,5,2
%N A085058 A001511(n) + 1.
%C A085058 Number of divisors of 2n of the form 2^k. - Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), 
               Jul 25 2007
%C A085058 Number of steps for iteration of map x -> (3/2)*ceiling(x) to reach an 
               integer when started at 2*n+1.
%C A085058 Also number of steps for iteration of map x -> (3/2)*floor(x) to reach 
               an integer when started at 2*n+3. - Benoit Cloitre, Sep 27 2003
%C A085058 The first time that a(n) = e+1 is when n is of the form 2^e - 1. - Robert 
               G. Wilson v Sep 28 2003. - Gary W. Adamson (qntmpkt(AT)yahoo.com), 
               Sep 29 2003
%C A085058 a(n) = A007814(3^(n+1) - (-1)^(n+1)) = A007814(A105723(n+1)). - Reinhard 
               Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 18 2005
%C A085058 Let 2^k(n) = largest power of 2 dividing tangent number T(n). Then a(n) 
               = 2*n-k(n). - Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp), Dec 
               23 2006
%H A085058 J. C. Lagarias and N. J. A. Sloane, Approximate squaring (<a href="http:/
               /www.research.att.com/~njas/doc/apsq.pdf">pdf</a>, <a href="http:/
               /www.research.att.com/~njas/doc/apsq.ps">ps</a>), Experimental Math., 
               13 (2004), 113-128.
%F A085058 a(n) = A001511(n) + 1 = A001511(2n). - Ray Chandler, Jul 29 2007
%p A085058 f := x->(3/2)*ceil(x); g := proc(n) local t1,c; global f; t1 := f(n); 
               c := 1; while not type(t1, 'integer') do c := c+1; t1 := f(t1); od; 
               RETURN([c,t1]); end;
%t A085058 g = 3 Ceiling[ # ]/2 &; f[n_?OddQ] := Length @ NestWhileList[ g, g[n], 
               !IntegerQ[ # ] & ]; Table[ f[n], {n, 1, 210, 2}]
%o A085058 (PARI) A085058(n)=if(n<0,0,c=2*n+7/2; x=0; while(frac(c)>0,c=3/2*floor(c); 
               x++); x) (from Benoit Cloitre)
%o A085058 (PARI) A085058(n)=if(n<0,0,c=(2*n+1)*3/2; x=1; while(frac(c)>0,c=3/2*ceil(c); 
               x++); x) (from Benoit Cloitre)
%Y A085058 Cf. A001511, A085060.
%Y A085058 Sequence in context: A066482 A089080 A123725 this_sequence A080771 A025477 
               A080189
%Y A085058 Adjacent sequences: A085055 A085056 A085057 this_sequence A085059 A085060 
               A085061
%K A085058 nonn
%O A085058 0,1
%A A085058 N. J. A. Sloane (njas(AT)research.att.com), Aug 11 2003