A262589 Number of other isonemal fabrics of exact period n.

0, 0, 2, 0, 4, 0, 40, 0, 64, 0, 316, 6, 448, 90, 3529, 14, 3836, 0

Offset

2,3

References

B. Grünbaum and G. C. Shephard, The geometry of fabrics, pp. 77-97 of F. C. Holroyd and R. J. Wilson, editors, Geometrical Combinatorics. Pitman, Boston, 1984. [gives different a(10) which is probably erroneous]

Links

Table of n, a(n) for n=2..19.

Branko Grünbaum and G. C. Shephard, A catalogue of isonemal fabrics, Discrete Geometry and Convexity, 440 (1985), 279-298.

B. Grünbaum and G. C. Shephard, An extension to the catalogue of isonemal fabrics, Discrete Mathematics, 60, (1986), 155-192.

Formula

A005441(n) = A000046(n) + A193140(n) + a(n).

Crossrefs

Cf. A000046, A005441, A193140.

Sequence in context: A019219 A019139 A285774 * A019215 A326799 A112081

Adjacent sequences: A262586 A262587 A262588 * A262590 A262591 A262592

Keyword

nonn,more

Author

N. J. A. Sloane, Oct 21 2015

Extensions

a(14)-a(19) using formula added, a(10) corrected by Andrey Zabolotskiy, Apr 14 2023

Status

approved