OFFSET
1,4
COMMENTS
a(18) and a(19) are incorrect. See A019473 for the correct version of this sequence. - Nathaniel Johnston, Aug 19 2018
LINKS
EXAMPLE
a(4)=2 because the block and the tub are the only 4-cell still lifes.
CROSSREFS
KEYWORD
dead
AUTHOR
N. J. A. Sloane, Aug 28 2000
STATUS
approved