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A044043
Number of tilings of 2 X n rectangle with polyominoes, each of which has area = # of adjacent polyominoes.
0
0, 0, 2, 5, 3, 9, 23, 25, 44, 113, 161, 244, 561, 930, 1405, 2865, 5137, 8062, 15082, 27806, 45582, 81210, 149637, 254034, 442904, 806389, 1400830, 2428499, 4362924, 7674434, 13329558, 23699803, 41904969, 73097351, 129121535, 228531847
OFFSET
1,3
FORMULA
Complicated linear recurrence in terms of 4 variables known.
Empirical g.f.: -x^3*(2*x^8 + 4*x^5 + 4*x^4 + 3*x^3 + 3*x^2 + 5*x + 2) / (2*x^10 + 4*x^7 + 3*x^6 + x^5 + 2*x^4 + 3*x^3 - 1). [Colin Barker, Nov 29 2012]
EXAMPLE
a(5)=3 because of the tilings
aaabb aabbb abbbc
ccddd cccdd adddc
CROSSREFS
Sequence in context: A361398 A332357 A305126 * A133128 A057337 A163233
KEYWORD
nonn
AUTHOR
I seem to have no record of the source for this sequence. - N. J. A. Sloane
STATUS
approved