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 A019473 Number of stable n-celled patterns ("still lifes") in Conway's Game of Life, up to rotation and reflection. 14
 0, 0, 0, 2, 1, 5, 4, 9, 10, 25, 46, 121, 240, 619, 1353, 3286, 7773, 19044, 45759, 112243, 273188, 672172, 1646147, 4051732, 9971377, 24619307, 60823008, 150613157, 373188952, 926068847, 2299616637, 5716948683, 14223867298, 35422864104 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS This sequence only counts still lifes that cannot be broken down into 2 or more smaller still lifes. That is, it only counts "strict" still lifes (contrast with A056613). - Nathaniel Johnston, Dec 11 2019 LINKS S. Ekström, Enumerating Still Lifes (in C) N. D. Elkies, The still-Life density problem and its generalizations, arXiv:math/9905194 [math.CO], 1999. H. Koenig, Stable Objects (another version of this sequence) Mark D. Niemiec, Life Object Counts R. C. Schroeppel, A few mathematical experiments Eric Weisstein's World of Mathematics, Game of Life EXAMPLE a(4)=2 because the block and the tub are the only 4-cell still lifes. CROSSREFS Cf. A056613, A056614, A056605, A330283. Sequence in context: A325771 A207480 A166517 * A056605 A091802 A144240 Adjacent sequences:  A019470 A019471 A019472 * A019474 A019475 A019476 KEYWORD hard,nonn,nice,changed AUTHOR EXTENSIONS More terms from Stephen A. Silver, Dec 11 1999 a(24) corrected, at the suggestion of Mark Niemiec, by Nathaniel Johnston, Aug 26 2016 a(24)-a(28) corrected, using data computed by Simon Ekström, by Adam P. Goucher, Jan 08 2017 a(31)-a(32) from Nathaniel Johnston, using a script made by Simon Ekström, May 25 2017 a(33) from Nathaniel Johnston, using a script made by Simon Ekström, Apr 05 2019 a(34) from Nathaniel Johnston, using a script made by Simon Ekström, Jan 09 2020 STATUS approved

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Last modified August 11 09:30 EDT 2020. Contains 336423 sequences. (Running on oeis4.)