What is the minimum number of pennies that can be placed upon a table so that each penny touches three, and only three, others?

(All the pennies must lie flat on the table.)

The building block of 080 where the loops of the 8 are pennies is the key here. SilverKnight's answer I think is correct, as you can't fit three of these building blocks together, but you can fit four.
Edited on December 30, 2003, 2:08 pm

Posted by Jack Squat on 2003-12-30 13:57:58