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A167435
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Hankel transform of A084076.
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2
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1, 2, -16, -3584, -1114112, -771751936, -68719476736, 50102545854496768, 4999067643975288487936, 1104958199127771065681444864, 363815722265501838229553819942912
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history;
text;
internal format)
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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) = 2^(n^2)*(-1)^n*Sum_{k=0..n} C(n+k,2k)*(-2)^(n-k).
a(n) = 2^(n^2)*[x^n](1-2*x)/(1+3*x+4*x^2) = 2^(n^2) *A247560(n).
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MATHEMATICA
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a[n_] := Sum[Binomial[n + k, 2*k]*(-2)^(n - k), {k, 0, n}]; Table[2^(n^2)*(-1)^n*a[n], {n, 0, 10}] (* G. C. Greubel, Jun 13 2016 *)
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CROSSREFS
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KEYWORD
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easy,sign
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AUTHOR
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STATUS
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approved
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