prob032: Maximum density still life

proposed by

b.m.smith @ hud.ac.uk

Robert A. Bosch, "Stable Patterns in Variants of Conway's Game of Life", Operations Research Letters 27(1), 7-11, (2000). Link to the electronic version.
Robert A. Bosch, "Integer Programming and Conway's Game of Life", SIAM Review 41(3), 596-604, (1999). Link to the electronic version.
Robert Bosch and Michael Trick, "Constraint Programming and Hybrid Formulations for Life", Workshop on Modelling and Problem Formulation (Formul'01), CP'01, December 2001.
Barbara Smith, "A Dual Graph Translation of a Problem in `Life'", Proceedings CP'02, 2002.