Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A005690
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A005690 Number of Twopins positions.
(Formerly M0999)
+0
1
1, 2, 4, 6, 9, 12, 18, 26, 41, 62, 96, 142, 212, 308, 454, 662, 979, 1438, 2128, 3126, 4606, 6748, 9910, 14510, 21298, 31212, 45820, 67176, 98571, 144476 (list; graph; listen)
OFFSET

8,2

REFERENCES

R. K. Guy, ``Anyone for Twopins?,'' in D. A. Klarner, editor, The Mathematical Gardner. Prindle, Weber and Schmidt, Boston, 1981, pp. 2-15.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

FORMULA

G.f.: [x^8]/[(x^3-x+1)(x^3+x-1)(x^6+x^2-1)]. - Ralf Stephan, Apr 22 2004

MAPLE

A005690:=1/(z**3+z-1)/(z**3-z+1)/(z**6+z**2-1); [Conjectured (correctly) by S. Plouffe in his 1992 dissertation.]

CROSSREFS

Sequence in context: A133041 A079492 A094660 this_sequence A005779 A098387 A135072

Adjacent sequences: A005687 A005688 A005689 this_sequence A005691 A005692 A005693

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 9 18:50 EST 2009. Contains 170568 sequences.


AT&T Labs Research