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A123846
Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 5x5 which is symmetric after a rotation by 90 degrees.
0
1, 1, 1, 1, 21, 31, 41, 421, 1937
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: A067599 A342838 A261322 * A336383 A168000 A031889
KEYWORD
nonn
AUTHOR
Søren Eilers, Oct 29 2006
STATUS
approved