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A140683
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3*(-1)^(n+1)*2^n-1.
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1
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-4, 5, -13, 23, -49, 95, -193, 383, -769, 1535, -3073, 6143, -12289, 24575, -49153, 98303, -196609, 393215, -786433, 1572863, -3145729, 6291455, -12582913, 25165823, -50331649, 100663295, -201326593, 402653183, -805306369, 1610612735, -3221225473
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Alternated reading of negative of A140660 and A140529.
The binomial transform yields -4 followed by the negative of A140657.
The inverse binomial transform yields essentially a signed version of A000244. - R. J. Mathar, Aug 02 2008.
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
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FORMULA
| a(2n)= -A140660(n). a(2n+1)= A140529(n).
a(n+1)-a(n)= (-1)^n*A005010(n). a(2n)+a(2n+1)= A096045(n).
a(n) = A140590(n+1)-2*A140590(n).
O.g.f: (4-x)/((x-1)(2x+1)). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 02 2008
a(0)=-4, a(1)=5, a(n)=-a(n-1)+2*a(n-2) [From Harvey P. Dale, May 26 2011]
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MATHEMATICA
| Table[3(-1)^(n+1)2^n-1, {n, 0, 40}] (* or *) LinearRecurrence[{-1, 2}, {-4, 5}, (* From Harvey P. Dale, May 26 2011 *)40]
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PROG
| (MAGMA) [3*(-1)^(n+1)*2^n-1: n in [0..40]]; // Vincenzo Librandi, Aug 08 2011
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CROSSREFS
| Sequence in context: A094029 A005672 A147001 * A071341 A102981 A029663
Adjacent sequences: A140680 A140681 A140682 * A140684 A140685 A140686
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KEYWORD
| sign
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Jul 11 2008
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EXTENSIONS
| Edited and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 02 2008
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