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A375316
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Expansion of (1 + x)/(1 - x^2*(1 + x)^4).
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0
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1, 1, 1, 5, 11, 19, 42, 98, 205, 429, 936, 2024, 4316, 9260, 19949, 42841, 91917, 197485, 424331, 911255, 1957086, 4203998, 9029949, 19394681, 41657808, 89478064, 192189304, 412801176, 886657081, 1904452689, 4090567673, 8786123349, 18871714923, 40534539675
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OFFSET
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0,4
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LINKS
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FORMULA
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a(n) = a(n-2) + 4*a(n-3) + 6*a(n-4) + 4*a(n-5) + a(n-6).
a(n) = Sum_{k=0..floor(n/2)} binomial(4*k+1,n-2*k).
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PROG
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(PARI) my(N=40, x='x+O('x^N)); Vec((1+x)/(1-x^2*(1+x)^4))
(PARI) a(n) = sum(k=0, n\2, binomial(4*k+1, n-2*k));
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CROSSREFS
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KEYWORD
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nonn,new
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AUTHOR
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STATUS
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approved
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