login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A123792 Number of ways to build a contiguous building with n LEGO blocks of size 1x5 on top of a fixed block of the same size so that the builing is flat, i.e. with all blocks in parallel position. 0
9, 91, 1089, 13726, 182736, 2493062, 34865595, 495114895, 7127585291 (list; graph; refs; listen; history; internal format)
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

REFERENCES

M. Abrahamsen and S. Eilers, Efficient counting of LEGO buildings, in preparation

B. Durhuus and S. Eilers, On the entropy of LEGO, arXiv:math.CO/0504039

LINKS

S. Eilers, LEGO counts

CROSSREFS

Sequence in context: A109108 A163456 A176735 * A022520 A020236 A068624

Adjacent sequences:  A123789 A123790 A123791 * A123793 A123794 A123795

KEYWORD

nonn,hard

AUTHOR

Soren Eilers (eilers(AT)math.ku.dk), Oct 29 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 13:28 EST 2012. Contains 206031 sequences.