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A167581
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The second left hand column of triangle A167580.
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5
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-1, 0, 28, 192, 880, 3328, 11200, 34816, 102144, 286720, 777216, 2048000, 5271552, 13303808, 33013760, 80740352, 194969600, 465567744, 1100742656, 2579496960, 5996806144, 13841203200, 31738298368, 72343355392, 163997286400
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OFFSET
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2,3
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LINKS
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FORMULA
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a(n) = 2^n*(2*n^3 - 9*n^2 + 10*n - 3)/12.
GF(z) = (4*z^2 + 8*z - 1)/(1-2*z)^4.
a(n) = 8*a(n-1) - 24*a(n-2) + 32*a(n-3) - 16*a(n-4)
a(n) - 7*a(n-1) + 18*a(n-2) - 20*a(n-3) + 8*a(n-4) = 1*2^(n-1)
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MATHEMATICA
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LinearRecurrence[{8, -24, 32, -16}, {-1, 0, 28, 192}, 30] (* Harvey P. Dale, Jan 22 2012 *)
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CROSSREFS
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Equals the second left hand column of triangle A167580.
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KEYWORD
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easy,sign
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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