

A056842


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


5



1, 6, 14, 64, 237, 1024, 4254, 18664, 81865, 365190, 1634801, 7388372
(list;
graph;
refs;
listen;
history;
text;
internal format)



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



EXAMPLE

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


CROSSREFS

Cf. A217720 (number of onesided polydrafters with n cells).
Cf. A289137 (number of extended [twosided] polydrafters with n cells).


KEYWORD

nonn,more,hard


AUTHOR



EXTENSIONS



STATUS

approved



