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A123845
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 180 degrees.
0
1, 1, 29, 143, 3497, 22303, 503847, 3778105
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OFFSET
1,3
LINKS
Table of n, a(n) for n=1..8.
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:
A023277
A299109
A302542
*
A297722
A042642
A172075
Adjacent sequences:
A123842
A123843
A123844
*
A123846
A123847
A123848
KEYWORD
nonn
AUTHOR
Søren Eilers
, Oct 29 2006
STATUS
approved
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Last modified April 18 02:22 EDT 2024. Contains 371767 sequences. (Running on oeis4.)