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A006749 Number of asymmetric polyominoes with n cells.
(Formerly M3906)
22

%I M3906

%S 0,0,0,1,5,20,84,316,1196,4461,16750,62878,237394,899265,3422111,

%T 13069026,50091095,192583152,742560511,2870523142,11122817672,

%U 43191285751,168046076423,654997492842,2557223459805,9999080270766,39152997087077,153511067364760

%N Number of asymmetric polyominoes with n cells.

%C This sequence counts polyominoes whose symmetry group has order 1.

%D A. R. Conway and A. J. Guttmann, On two-dimensional percolation, J. Phys. A: Math. Gen. 28(1995) 891-904.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Tomás Oliveira e Silva, <a href="http://sweet.ua.pt/tos/animals.html">Enumeration of polyominoes</a>

%H T. R. Parkin, L. J. Lander, and D. R. Parkin, <a href="/A000104/a000104.pdf">Polyomino Enumeration Results</a>, presented at SIAM Fall Meeting, 1967) and accompanying letter from T. J. Lander (annotated scanned copy). See page 21.

%H D. H. Redelmeier, <a href="http://dx.doi.org/10.1016/0012-365X(81)90237-5">Counting polyominoes: yet another attack</a>, Discrete Math., 36 (1981), 191-203.

%H D. H. Redelmeier, <a href="/A056877/a056877.png">Table 3</a> of Counting polyominoes...

%Y Cf. A000105, A001168, A006746, A056877, A006748, A056878, A006747, A006749, A006884, A006885, A006877, A006878, A033492.

%Y Sequences classifying polyominoes by symmetry group: A000105, A006746, A006747, A006748, A006749, A056877, A056878, A142886, A144553, A144554.

%K nonn,nice

%O 1,5

%A _N. J. A. Sloane_

%E Extended to n=28 by Tomás Oliveira e Silva.

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Last modified October 13 20:38 EDT 2019. Contains 327981 sequences. (Running on oeis4.)