%I #8 Jun 18 2016 11:15:22
%S 0,0,1,2,11,40
%N Number of distinct irregular n-gon flexagons.
%D Les Pook, Flexagons inside out, Cambridge University Press, 2003, p. 84.
%e a(6) = 11, because there are 11 distinct irregular hexaflexagons.
%Y Cf. A001683.
%K nonn,hard,more
%O 2,4
%A _Christian Schroeder_, Jun 18 2016