%I A056842
%S A056842 1,6,14,64,237,1024,4254,18664,81865
%N A056842 Number of polydrafters: a(n) is the number of polydrafters with n cells. 
               See the Paterson link for the definition.
%C A056842 Restatement of the definition: A polydrafter is a polygon formed by joining 
               30-60-90 triangles, according to the following rules:
%C A056842 (a) Two triangles may be joined along their short legs, with their right 
               angles touching;
%C A056842 (b) Two triangles may be joined along their long legs, with their right 
               angles touching;
%C A056842 (c) Two triangles may be joined along their hypotenuses, in either direction;
%C A056842 (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.
%D A056842 Ed Pegg, Jr., Polyform puzzles, in Tribute to a Mathemagician, Peters, 
               2005, pp. 119-125.
%H A056842 D. Paterson, <a href="http://mathforum.org/epigone/geometry-puzzles/floucrerdgrex">
               Pentominos & Dodecadudes</a>
%H A056842 M. Vicher, <a href="http://www.vicher.cz/puzzle/polyforms.htm">Polyforms</
               a>
%H A056842 M. Vicher, <a href="http://www.vicher.cz/puzzle/polyform/tridr/triddr.html">
               Tridrafters</a>
%H A056842 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Polydrafter.html">Link to a section of The World of Mathematics.</
               a>
%e A056842 a(3) = 14 because there are 14 tridafters. The second Vicher link shows 
               various arrangements of them.
%Y A056842 Sequence in context: A032404 A059954 A139257 this_sequence A130263 A077401 
               A158965
%Y A056842 Adjacent sequences: A056839 A056840 A056841 this_sequence A056843 A056844 
               A056845
%K A056842 nonn,more
%O A056842 1,2
%A A056842 James A. Sellers (sellersj(AT)math.psu.edu), Aug 28 2000
%E A056842 Edited by David R. Wasserman (wasserma(AT)spawar.navy.mil), Dec 01 2003