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A371429
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Expansion of (1/x) * Series_Reversion( x / ((1+x)^3 - x^4) ).
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1
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1, 3, 12, 55, 272, 1413, 7599, 41933, 236053, 1350093, 7822620, 45817390, 270815730, 1613300978, 9676131942, 58380176644, 354081959367, 2157570900137, 13201923181308, 81084900544971, 499711105642851, 3089163236655363, 19150916212748940, 119031956868317285
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} (-1)^k * binomial(n+1,k) * binomial(3*n-3*k+3,n-4*k).
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PROG
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(PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/((1+x)^3-x^4))/x)
(PARI) a(n) = sum(k=0, n\4, (-1)^k*binomial(n+1, k)*binomial(3*n-3*k+3, n-4*k))/(n+1);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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