0,3

Also the number of polybricks of size n made of Lego.

Ed Pegg, Jr., Illustrations of polyforms

M. Keller, More information

M. Vicher, Polyforms

Eric Weisstein's World of Mathematics, Polyrhomb [From Eric W. Weisstein (eric(AT)weisstein.com), Apr 24 2009]

Cf. A057973.

Sequence in context: A030238 A110490 A132868 this_sequence A071688 A110149 A024331

Adjacent sequences: A056780 A056781 A056782 this_sequence A056784 A056785 A056786

nonn

James A. Sellers (sellersj(AT)math.psu.edu), Aug 28 2000

More terms from Don Reble (djr(AT)nk.ca), Nov 01 2001