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A151523
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Number of 1-sided strip polyrhombs with n cells.
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4
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1, 2, 4, 10, 20, 48, 106, 252, 578, 1372, 3208, 7584, 17850, 42102, 99276, 233716, 550960, 1295146, 3050226, 7161346, 16846668, 39511876, 92845830
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OFFSET
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1,2
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COMMENTS
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Also counts 1-sided strip polyrects.
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LINKS
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Eric Weisstein's World of Mathematics, Polyrhomb
Eric Weisstein's World of Mathematics, Polyrect
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CROSSREFS
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Strip polyominoes by group of symmetries relating shapes considered the same: A002013 (all symmetries), A182644 (translations only), A151514 (rotations and translations), A151527 (horizontal and vertical reflections, rotations of order 2 and translations), A151524 (reflections in either diagonal, rotations of order 2 and translations), A151523 (rotations of order 2 and translations), A151526 (reflections in a horizontal line and translations), A182646 (reflections in a NE-SW diagonal line and translations)
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KEYWORD
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nonn,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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