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A070765 Number of polyiamonds with n cells, without holes. 7
1, 1, 1, 3, 4, 12, 24, 66, 159, 444, 1161, 3226, 8785, 24453, 67716, 189309, 528922, 1484738, 4172185, 11756354, 33174451, 93795220, 265565628, 753060469, 2138206966, 6078931114, 17302380313, 49302121747, 140627400927, 401510058179 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

If holes are allowed, we get A000577.

LINKS

Table of n, a(n) for n=1..30.

Elena V. Konstantinova and Maxim V. Vidyuk, Discriminating tests of information and topological indices. Animals and trees, J. Chem. Inf. Comput. Sci. 43 (2003), 1860-1871.

Hai Pham-Van, Linh Tran-Phan-Thuy, Cuong Tran-Manh, Bich Do-Danh, Hoang Luc-Huy, Two-Dimensional Clusters of Colloidal Particles Induced by Emulsion Droplet Evaporation, Nanomaterials (2020) Vol. 10, 156.

CROSSREFS

Equals A000577(n)-A070764(n). Cf. A000104, A018190.

Sequence in context: A073713 A291023 A084921 * A000577 A333163 A111758

Adjacent sequences:  A070762 A070763 A070764 * A070766 A070767 A070768

KEYWORD

hard,nonn

AUTHOR

Joseph Myers, May 05 2002

EXTENSIONS

More terms from Joseph Myers, Nov 11 2003

a(29) and a(30) from Joseph Myers, Nov 21 2010

STATUS

approved

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Last modified October 16 07:07 EDT 2021. Contains 348041 sequences. (Running on oeis4.)