%I A019473
%S A019473 0,0,0,2,1,5,4,9,10,25,46,121,240,619,1353,3286,7773,19044,45759,
%T A019473 112243,273188,672172,1646147,4051711
%N A019473 Number of stable n-celled patterns ("still lifes") in Conway's game of 
               Life.
%H A019473 N. D. Elkies, <a href="http://arXiv.org/abs/math.CO/9905194">[math/9905194] 
               The still-Life density problem and its generalizations</a>
%H A019473 H. Koenig, <a href="http://www.pentadecathlon.com/LifeInfo/Objects/Class1/
               Stable.html">Stable Objects</a> (another version of this sequence)
%H A019473 Mark D. Niemiec, <a href="http://home.interserv.com/~mniemiec/objcount.htm">
               Life Object Counts</a>
%H A019473 R. C. Schroeppel, <a href="http://www.experimentalmath.info/workshop2004/
               schroeppel-talk.pdf">A few mathematical experiments</a>
%H A019473 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Life.html">Life</a>
%H A019473 R. Munafo, <a href="http://www.mrob.com/pub/math/seq-a019473.html">Still-Lifes 
               with N cells in Conway's game of Life</a>
%e A019473 a(4)=2 because the block and the tub are the only 4-cell still lifes.
%Y A019473 Cf. A056613, A056614, A056605.
%Y A019473 Sequence in context: A159930 A058344 A010582 this_sequence A056605 A091802 
               A144240
%Y A019473 Adjacent sequences: A019470 A019471 A019472 this_sequence A019474 A019475 
               A019476
%K A019473 hard,nonn,nice
%O A019473 1,4
%A A019473 Robert P. Munafo (mrob(AT)mrob.com)
%E A019473 More terms from Stephen A. Silver (maths(AT)argentum.freeserve.co.uk)