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A123781 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 4 which is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees. 0
1, 1, 5, 7, 41, 65, 384, 649, 3853, 6745, 40209, 72334, 431188, 791144, 4717533, 8787824, 52396271, 98784645 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
CROSSREFS
Sequence in context: A235365 A189241 A167205 * A120298 A178342 A117751
KEYWORD
nonn,more
AUTHOR
Søren Eilers, Oct 29 2006
EXTENSIONS
More terms by Søren Eilers, Sep 12 2018
STATUS
approved

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Last modified March 29 09:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)