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A123834 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 3 X 3 which is symmetric after a rotation by 90 degrees. 0
1, 1, 1, 1, 7, 10, 13, 50, 190, 292, 403, 1873, 6982 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,5
LINKS
M. Abrahamsen and S. Eilers, On the asymptotic enumeration of LEGO structures, Exper Math. 20 (2) (2011) 145-152.
B. Durhuus and S. Eilers, On the entropy of LEGO, arXiv:math.CO/0504039
CROSSREFS
Sequence in context: A219045 A199427 A178508 * A064629 A215579 A306469
KEYWORD
nonn
AUTHOR
Søren Eilers, Oct 29 2006
STATUS
approved

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Last modified May 18 02:04 EDT 2024. Contains 372615 sequences. (Running on oeis4.)