1,2

Comment from Larry_Reeves(AT)intranetsolutions.com, Jun 22 2001: If you look at Vicher's picture of the 40 4-celled polydiamonds (link in A056844), near the middle of the picture is a polydiamond that looks like the tradiitional 2-D representation of a cube with an extra diamond stuck to the edge. Depending on how you orient the cube, there are actually 2 different ways to form this polydiamond, although there is no change in the perimeter shape. I haven't confirmed that this explains the difference in values for sizes 5 and above for A056844 and A056845, but it looks like a possible explanation.

M. Vicher, Polyforms

M. Vicher, The 40 4-celled polydiamonds

M. Vicher, The 40 4-celled polydiamonds

Cf. A056845.

Sequence in context: A052512 A038156 A052846 this_sequence A002825 A052322 A130767

Adjacent sequences: A056841 A056842 A056843 this_sequence A056845 A056846 A056847

nice,nonn

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

Edited by njas, Jun 21, 2001