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A047875 Size of smallest polyomino with surround number n (the surround number of a polyomino is the number of different ways that it can be surrounded by non-overlapping copies of the same polyomino). 5
7, 1, 5, 9, 8, 9, 9, 4, 8, 7, 9, 9, 9, 9, 8, 9, 6, 9, 8, 8, 9, 8, 8, 7, 9, 8, 7, 8, 8, 9, 8, 8, 9, 9, 8, 9, 9, 9, 9, 8, 9, 6, 8, 9, 10, 9, 9, 8, 6, 7, 8, 8, 8, 9, 8, 9, 9, 9, 10, 9, 9, 8, 9, 9, 9, 9, 9, 9, 9, 8, 9, 9, 7, 8, 8, 9, 9, 7, 8, 7, 9, 9, 9, 9, 9, 9, 8, 9, 9, 9, 9, 9, 9, 9, 8, 9, 9, 8, 9, 9, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

REFERENCES

W. F. Lunnon, Counting polyominoes, pp. 347-372 of A. O. L. Atkin and B. J. Birch, editors, Computers in Number Theory. Academic Press, NY, 1971.

LINKS

Table of n, a(n) for n=0..100.

E. J. Friedman, Math. Magic

EXAMPLE

a(2) = 5 because the smallest polyomino which has a surround number 2 is

..X..

.XXX.

..X..

CROSSREFS

Cf. A000105.

Sequence in context: A118307 A178757 A195369 * A064467 A089204 A107786

Adjacent sequences:  A047872 A047873 A047874 * A047876 A047877 A047878

KEYWORD

nonn

AUTHOR

Brendan Owen (bdowen(AT)ee.mu.oz.au)

STATUS

approved

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Last modified October 21 11:42 EDT 2019. Contains 328296 sequences. (Running on oeis4.)