OFFSET
1,2
COMMENTS
Side numbers range from 3 to 8. See Wang and Hsiung (1942). - Douglas J. Durian, Sep 24 2017
LINKS
Douglas J. Durian, Table of n, a(n) for n = 1..750
Douglas J. Durian, Illustration of shapes for n=1..20.
Eli Fox-Epstein, Ryuhei Uehara, The Convex Configurations of "Sei Shonagon Chie no Ita" and Other Dissection Puzzles, arXiv:1407.1923 [cs.CG], (8-July-2014)
Eli Fox-Epstein, Kazuho Katsumata, Ryuhei Uehara, The Convex Configurations of “Sei Shonagon Chie no Ita,” Tangram, and Other Silhouette Puzzles with Seven Pieces, Institute of Electronics, Information Communication Engineers - Transactions on Fundamentals, E99-A (2016), 1084-1089.
Paul Scott, Convex Tangrams, Australian Mathematics Teacher, 62 (2006), 2-5. Confirms a(16)=20.
Fu Traing Wang and Chuan-Chih Hsiung, A Theorem on the Tangram, American Mathematical Monthly, 49 (1942), 596-599. Proves a(16)=20 and that convex polyabolos have no more than eight sides.
Douglas J. Durian, Description of shapes for n = 1..750
FORMULA
EXAMPLE
For n=3, there are two trapezoids.
CROSSREFS
KEYWORD
nonn
AUTHOR
Eli Fox-Epstein, Jul 29 2014
EXTENSIONS
Definition clarified by Douglas J. Durian, Sep 24 2017
a(51) and beyond from Douglas J. Durian, Jan 24 2020
STATUS
approved