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 A112088 Number of leaf nodes in a binary tree. 77
 2, 3, 5, 7, 11, 16, 24, 36, 54, 81, 122, 183, 274, 411, 617, 925, 1388, 2082, 3123, 4684, 7026, 10539, 15809, 23713, 35570, 53355, 80032, 120048, 180072, 270108, 405162, 607743, 911615, 1367422, 2051133, 3076700, 4615050, 6922575, 10383862 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Seiichi Manyama, Table of n, a(n) for n = 1..5678 (terms 1..1000 from David W. Wilson) Simon Strandgaard, About this sequence FORMULA a(1)=2; a(n)=floor((5+sum(a(1) to a(n-1)))/2). - Graeme McRae, Jun 09 2006 MATHEMATICA f[n_] := Block[{a = 2, b = 0, c = 4}, Do[x = b + a; c -= x; If[c < 0, a *= 2; c += 2a]; b = Floor[(2a - c + 1)/2], {i, n}]; x]; Array[f, 40] (* Robert G. Wilson v, Jan 11 2006 *)) f[s_] := Append[s, Ceiling[2 + Plus @@ s/2]]; Nest[f, {2}, 38] (* Robert G. Wilson v, Jul 08 2006 *) PROG (Ruby) a, c=2, 4; p Array.new(99){c-=x=(a*4-c+1)/2; c+=2*a*=2 if c<0; x} a:=2; b:=0; c:=4; p := proc() local x; global a, b, c; x := b + a; c := c - x; if(c<0) then a := a*2; c := c + a*2; end if; b := floor((a*2-c+1) / 2); x end proc: seq(p(), i=0..40); (PARI) first(n)=my(v=vector(n), s); v[1]=s=2; for(n=2, n, s+=v[n]=(s+5)\2); v \\ Charles R Greathouse IV, Nov 07 2016 CROSSREFS Sequence in context: A091501 A286271 A083198 * A117792 A154888 A271485 Adjacent sequences:  A112085 A112086 A112087 * A112089 A112090 A112091 KEYWORD easy,nonn AUTHOR Simon Strandgaard (neoneye(AT)gmail.com), Nov 29 2005 STATUS approved

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Last modified December 14 05:17 EST 2018. Contains 318090 sequences. (Running on oeis4.)