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A038578 Number of self-avoiding closed walks from 0 of area n in strip Z X {-1,0,1}. 7
1, 8, 16, 40, 88, 184, 388, 800, 1628, 3288, 6584, 13096, 25904, 50984, 99916, 195072, 379572, 736360, 1424672, 2749672, 5295240, 10176856, 19522644, 37387424, 71487756, 136492216, 260255304, 495618408, 942731360, 1791241544, 3399976348 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

J. Labelle, Self-avoiding walks and polyominoes in strips, Bull. ICA, 23 (1998), 88-98.

LINKS

Table of n, a(n) for n=0..30.

FORMULA

G.f.=-3+4(1-x^2+x^4)/(1-x-x^2-x^3)^2 [Labelle]. - Emeric Deutsch, Apr 29 2004

CROSSREFS

Cf. A022444.

Sequence in context: A024700 A108576 A052207 * A155110 A245419 A266159

Adjacent sequences:  A038575 A038576 A038577 * A038579 A038580 A038581

KEYWORD

nonn,walk,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Emeric Deutsch, Apr 29 2004

STATUS

approved

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Last modified December 11 07:47 EST 2019. Contains 329914 sequences. (Running on oeis4.)