

A056842


Number of polydrafters: a(n) is the number of polydrafters with n cells.


4




OFFSET

1,2


COMMENTS

See the Paterson link for the definition.
Restatement of the definition: A polydrafter is a polygon formed by joining 306090 triangles, according to the following rules:
(a) Two triangles may be joined along their short legs, with their right angles touching;
(b) Two triangles may be joined along their long legs, with their right angles touching;
(c) Two triangles may be joined along their hypotenuses, in either direction;
(d) The short leg of triangle 1 may be joined to half of the hypotenuse of triangle 2, with the right angle of triangle 1 touching the midpoint of the hypotenuse of triangle 2.


REFERENCES

Ed Pegg, Jr., Polyform puzzles, in Tribute to a Mathemagician, Peters, 2005, pp. 119125.


LINKS

Table of n, a(n) for n=1..9.
D. Paterson, Pentominos & Dodecadudes
M. Vicher, Polyforms
M. Vicher, Tridrafters
Eric Weisstein's World of Mathematics, Polydrafter.


EXAMPLE

a(3) = 14 because there are 14 tridafters. The second Vicher link shows various arrangements of them.


CROSSREFS

Sequence in context: A059954 A252541 A139257 * A182752 A200033 A219376
Adjacent sequences: A056839 A056840 A056841 * A056843 A056844 A056845


KEYWORD

nonn,more


AUTHOR

James A. Sellers, Aug 28 2000


EXTENSIONS

Edited by David Wasserman, Dec 01 2003


STATUS

approved



