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A123778
Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1x4.
0
1, 12, 425, 17610, 818803, 40408828, 2078794759, 110210311068
OFFSET
1,2
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Søren Eilers, Oct 29 2006
STATUS
approved