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A123841
Number of ways to build a contiguous building with n LEGO blocks of size 4 X 4 on top of a fixed block of the same size.
0
49, 2917, 227409, 19212343, 1755695725, 167208276251, 16479170104225
OFFSET
1,1
COMMENTS
The base block is not counted among the n and must be the only block in the bottom layer of the building
LINKS
M. Abrahamsen and S. Eilers, Efficient counting of LEGO structures (2007).
B. Durhuus and S. Eilers, On the entropy of LEGO, arXiv:math/0504039 [math.CO], 2005.
S. Eilers, A LEGO Counting problem, 2005.
CROSSREFS
Sequence in context: A203384 A099367 A307811 * A014773 A376092 A132539
KEYWORD
nonn,hard
AUTHOR
Søren Eilers, Oct 29 2006
STATUS
approved