A213860 - OEIS

A213860

Number of free poly-IH22-tiles (holes allowed) with n cells.

1, 3, 8, 30, 106, 413, 1616, 6525, 26588, 109900, 457964, 1924270, 8135692, 34592460, 147780810

(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

CROSSREFS

KEYWORD

hard,more,nonn

AUTHOR

Joseph Myers, Jun 26 2012

STATUS

approved