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A005684 Number of Twopins positions.
(Formerly M1019)
1
1, 2, 4, 6, 11, 18, 32, 52, 88, 142, 236, 382, 629, 1018, 1664, 2692, 4383, 7092, 11520, 18640, 30232, 48916, 79264, 128252, 207705, 336074, 544084 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,2

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

Table of n, a(n) for n=6..32.

R. K. Guy, Anyone for Twopins?, in D. A. Klarner, editor, The Mathematical Gardner. Prindle, Weber and Schmidt, Boston, 1981, pp. 2-15. [Annotated scanned copy, with permission]

Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992.

Simon Plouffe, 1031 Generating Functions and Conjectures, Université du Québec à Montréal, 1992.

Index entries for linear recurrences with constant coefficients, signature (2,0,-2,3,-2,0,0,-1).

FORMULA

G.f.: x^6/( (x^2+x-1)*(x^2-x+1)*(x^4+x^2-1) ). - Ralf Stephan, Apr 21 2004

MAPLE

A005684:=1/(z**2-z+1)/(z**2+z-1)/(z**4+z**2-1); [Simon Plouffe in his 1992 dissertation.]

CROSSREFS

Sequence in context: A168445 A185192 A007053 * A260697 A018167 A295831

Adjacent sequences:  A005681 A005682 A005683 * A005685 A005686 A005687

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified May 26 13:05 EDT 2019. Contains 323586 sequences. (Running on oeis4.)