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A248158
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Expansion of (1 - 2*x^2)/(1 + x)^3. Second column of Riordan triangle A248156.
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3
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1, -3, 4, -4, 3, -1, -2, 6, -11, 17, -24, 32, -41, 51, -62, 74, -87, 101, -116, 132, -149, 167, -186, 206, -227, 249, -272, 296, -321, 347, -374, 402, -431, 461, -492, 524, -557, 591, -626, 662, -699, 737, -776, 816, -857, 899, -942, 986
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OFFSET
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0,2
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COMMENTS
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This is the column k=1 sequence of the Riordan triangle A248156 without a leading zero.
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LINKS
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FORMULA
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O.g.f.: (1 - 2*x^2)/(1 + x)^3 = -2/(1 + x) + 4/(1 + x)^2 - 1/(1 + x)^3.
a(n) = (-1)^n*(4*(2*n+1) - (n+1)*(n+2))/2, n >= 0.
a(n) = -3*(a(n-1) + a(n-2)) - a(n-3), n >= 3 with a(0) = 1, a(1) = -3 and a(2) = 4.
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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