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A213950 Number of free poly-IH9-tiles (holes allowed) with n cells. 0
1, 2, 7, 24, 99, 416, 1852, 8386, 38798, 181531, 858570, 4092042, 19636172, 94750922 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

Branko Gr├╝nbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 6.2 and 9.4.

LINKS

Table of n, a(n) for n=1..14.

CROSSREFS

Sequence in context: A150435 A150436 A197553 * A123764 A150437 A150438

Adjacent sequences:  A213947 A213948 A213949 * A213951 A213952 A213953

KEYWORD

hard,nonn,more

AUTHOR

Joseph Myers, Jun 26 2012

STATUS

approved

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Last modified December 5 20:45 EST 2019. Contains 329779 sequences. (Running on oeis4.)