%I M3489 #15 Nov 19 2022 01:10:34
%S 1,1,1,4,14,74,434,2876,19848,143306,1062149,8058223,62259820,
%T 488630360,3886211100,31267852668
%N Number of hexaflexagons with 3n triangles that can be folded from a straight strip of paper.
%D M. Kosters, A theory of hexaflexagons, Nieuw Archief Wisk., 17 (1999), 349-362.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%Y Cf. A001683, A000207.
%K nonn,more,nice
%O 1,4
%A _N. J. A. Sloane_, frb6006(AT)cs.rit.edu (Frank R. Bernhart)
%E More terms from Mike Godfrey (m.godfrey(AT)umist.ac.uk), Apr 02 2002