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A247745
Total number of Y shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.
2
0, 0, 0, 12, 224, 2096, 17732, 160624, 1498176, 13404068, 115123856, 980282312, 8327179132, 70264899456, 587727020332, 4882463109244, 40378339971868, 332612594766452, 2729309532474820, 22316919930250328, 181922495487675520, 1479018078159317720
OFFSET
0,4
LINKS
Wikipedia, Pentomino
FORMULA
a(n) = Sum_{k>0} k * A247712(n,k).
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 23 2014
STATUS
approved