login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

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