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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A089071 Number of liberties a big eye of size n gives in the game of Go. 6
1, 2, 3, 5, 8, 12, 17, 23, 30, 38, 47, 57, 68, 80, 93, 107, 122, 138, 155, 173, 192, 212, 233, 255, 278, 302, 327, 353, 380, 408, 437, 467, 498, 530, 563, 597, 632, 668, 705, 743, 782, 822, 863, 905, 948, 992, 1037, 1083, 1130, 1178, 1227, 1277, 1328, 1380 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The terms after the seventh are considered only of theoretical importance, since the largest dead shape is six spaces.

LINKS

Senseis Library, Big Eye Liberties

FORMULA

a(n)=a(n-1)+n-2 for n>=3.

Contribution from Paul Barry (pbarry(AT)wit.ie), Dec 07 2009: (Start)

G.f.: (1-x+x^3)/(1-x)^3;

a(n)=n+1-0^n+C(n-1,2). (End)

a(n) = A022856(n+2). - R. J. Mathar, Oct 30 2011

EXAMPLE

A 5-space big eye can be almost filled in 4 moves, after which one takes and has a 4-space big eye (5 liberties) left. This gives a total of 4+5 moves for the opponent and 1 for oneself, for de facto 8 liberties.

MATHEMATICA

i=-1; s=3; lst={Abs[i], s+i}; Do[s+=n+i; If[s>2, AppendTo[lst, s]], {n, 0, 6!, 1}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 30 2008]

CROSSREFS

Sequence in context: A028955 A104664 A022856 * A177205 A175829 A175827

Adjacent sequences:  A089068 A089069 A089070 * A089072 A089073 A089074

KEYWORD

nonn,easy

AUTHOR

Andre Engels (engelsAG(AT)t-online.de), Dec 03 2003

EXTENSIONS

More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Aug 29 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 03:44 EST 2012. Contains 205860 sequences.