A084240 - OEIS

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A084240

a(n)=-5a(n-1)-4a(n-2), a(0)=1, a(1)=0.

1, 0, -4, 20, -84, 340, -1364, 5460, -21844, 87380, -349524, 1398100, -5592404, 22369620, -89478484, 357913940, -1431655764, 5726623060, -22906492244, 91625968980, -366503875924, 1466015503700, -5864062014804, 23456248059220, -93824992236884, 375299968947540 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	COMMENTS	`A Jacobsthal related sequence.` `Inverse binomial transform of A084246. (-1)^n(1-A002450(n)).`
	FORMULA	`a(n)=4(-1)^n/3-(-4)^n/3; G.f.: (1+5x)/((1+x)(1+4x)); E.g.f.: (4exp(-x)-exp(-4*x))/3.` `a(n)=A084241(n)+(-1)^n a(n)=(-1)^(n+1)(A002450(n)-1)=(-1)^(n+1)(A001045(2n)-1).` `a(n)=(4(-1)^n-(-4)^n)/3; G.f.: (1+5x)/((1+x)(1+4x)).`
	CROSSREFS	`Cf. A001045.` `Sequence in context: A003489 A167682 A155721 * A080674 A110154 A158608` `Adjacent sequences: A084237 A084238 A084239 * A084241 A084242 A084243`
	KEYWORD	`easy,sign`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), May 23 2003`

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Last modified February 15 07:42 EST 2012. Contains 205717 sequences.