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A190569 Number of n-step one-sided prudent walks, avoiding single west steps and single east steps. 0
1, 3, 7, 13, 25, 51, 103, 205, 409, 819, 1639, 3277, 6553, 13107, 26215, 52429, 104857, 209715, 419431, 838861, 1677721, 3355443, 6710887, 13421773, 26843545, 53687091, 107374183, 214748365, 429496729, 858993459, 1717986919, 3435973837 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = A007909(n+2).

REFERENCES

S. Gao, H. Niederhausen, Sequences Arising From Prudent Self-Avoiding Walks (submitted to INTEGERS: The Electronic Journal of Combinatorial Number Theory).

LINKS

Table of n, a(n) for n=1..32.

FORMULA

G.f.: (1-x+2*x^2)/((1-2*x)*(1+x^2)).

CROSSREFS

Essentially a duplicate of A007909.

Sequence in context: A275788 A169914 A078000 * A007909 A282913 A284026

Adjacent sequences:  A190566 A190567 A190568 * A190570 A190571 A190572

KEYWORD

nonn,walk

AUTHOR

Shanzhen Gao, May 12 2011

STATUS

approved

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Last modified November 19 19:18 EST 2019. Contains 329323 sequences. (Running on oeis4.)