

A005441


Number of isonemal fabrics of period exactly n.
(Formerly M3230)


3



1, 1, 4, 4, 9, 8, 55, 21, 104, 62, 429, 196, 800, 698, 4674, 2070, 7721, 7154
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OFFSET

2,3


REFERENCES

B. Grünbaum and G. C. Shephard, The geometry of fabrics, pp. 7797 of F. C. Holroyd and R. J. Wilson, editors, Geometrical Combinatorics. Pitman, Boston, 1984. [gives different a(10) which is probably erroneous]
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS



FORMULA



CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS

a(14)a(19) from second Grünbaum and Shephard paper added by Sean A. Irvine, Jun 26 2016


STATUS

approved



