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0, -1, 2, -3, 4, -5, 6, -7, 8, -9, 10, -11, 12, -13, 14, -15, 16, -17, 18, -19, 20, -21, 22, -23, 24, -25, 26, -27, 28, -29, 30, -31, 32, -33, 34, -35, 36, -37, 38, -39, 40, -41, 42, -43, 44, -45, 46, -47, 48, -49, 50, -51, 52, -53, 54, -55, 56, -57, 58, -59, 60, -61, 62, -63, 64, -65
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| a(n) = determinant of the (n+1) X (n+1) matrix with 0's in the main diagonal and 1's elsewhere. - Franz Vrabec (franz.vrabec(AT)aon.at), Dec 01 2007
Sum{n>0} 1/a(n) = -log(2) [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Feb 24 2009]
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..2000
Tanya Khovanova, Recursive Sequences
Index to sequences with linear recurrences with constant coefficients, signature (-2,-1).
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FORMULA
| G.f.: -x/(1+x)^2.
E.g.f: -x*exp(-x).
a(0)=0, a(1)=-1, a(n)=-2*a(n-1)-a(n-2) for n>=2 [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Feb 24 2009]
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MAPLE
| A038608 := n->n*(-1)^n;
a:=n->sum((-1)^n, j=0..n-1): seq(a(n), n=0..73); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 17 2008]
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MATHEMATICA
| lst={}; Do[AppendTo[lst, n*(-1)^n], {n, 0, 6!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 18 2009]
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PROG
| (MAGMA) [n*(-1)^n: n in [0..80]]; // Vincenzo Librandi, Jun 08 2011
(PARI) a(n)=n*(-1)^n \\ Charles R Greathouse IV, Dec 07 2011
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CROSSREFS
| Cf. A002162, A155988. [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Feb 24 2009]
Sequence in context: A001478 A001489 * A105811 A104661 A069782 A088480
Adjacent sequences: A038605 A038606 A038607 * A038609 A038610 A038611
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KEYWORD
| sign,easy
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AUTHOR
| Vasiliy Danilov (danilovv(AT)usa.net) 1998 Jul
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EXTENSIONS
| Edited by Frank Ellermann (hmdmhdfmhdjmzdtjmzdtzktdkztdjz(AT)gmail.com), Jan 28 2002
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