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A217783
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Expansion of (1-x)*(1-2x)/((1-5x+5*x^2)*(1-3x+x^2)).
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1
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1, 5, 21, 83, 318, 1196, 4445, 16389, 60097, 219527, 799734, 2907800, 10558041, 38297573, 138819053, 502925211, 1821362830, 6594366404, 23870720757, 86396702117, 312668994969, 1131463798415, 4094241931526, 14814592074288, 53603587025713, 193949782284101
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OFFSET
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0,2
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COMMENTS
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A diagonal of the square array A217770.
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LINKS
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FORMULA
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a(n) = 8*a(n-1) -21*a(n-2) + 20*a(n-3) -5*a(n-4) for n>=4, a(0) = 1, a(1) = 5, a(2) = 21, a(3) = 83.
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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