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A224422
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Expansion of (1-x)*(1-3*x)/(1-9*x+28*x^2-35*x^3+15*x^4-x^5).
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6
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1, 5, 20, 75, 275, 1001, 3639, 13243, 48280, 176341, 645150, 2363596, 8669142, 31825005, 116914020, 429737220, 1580244061, 5812839156, 21387636101, 78708626396, 289699273501, 1066406842677, 3925882147566, 14453780545834, 53216783798234, 195944670698910
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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 A223968.
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LINKS
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FORMULA
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a(n) = 9*a(n-1) - 28*a(n-2) + 35*a(n-3) - 15*a(n-4) + a(n-5) with a(0) = 1, a(1) = 5, a(2) = 20, a(3) = 75, a(4) = 275.
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MATHEMATICA
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LinearRecurrence[{9, -28, 35, -15, 1}, {1, 5, 20, 75, 275}, 26] (* Michael De Vlieger, Aug 05 2021 *)
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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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