id:A163980 - OEIS Search Results

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2*n+(-1)^n.

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	OFFSET	`1,2`
	FORMULA	`a(n)=A005843(n)-(-1)^A001477(n)=2A000027(n)+(-1)^A000027(n)=A005843(n)+A033999(n).` `a(n)= a(n-1)+a(n-2)-a(n-3). G.f.: x(1+4x-x^2)/((1+x)(x-1)^2). [R. J. Mathar, Aug 21 2009]`
	EXAMPLE	`a(1)=2-(-1)^0=1. a(2)=4-(-1)^1=5. a(3)=6-(-1)^2=5.`
	CROSSREFS	`Cf. A000027, A004442, A005843, A033999.` `Sequence in context: A030798 A021951 A124175 this_sequence A011986 A047880 A058491` `Adjacent sequences: A163977 A163978 A163979 this_sequence A163981 A163982 A163983`
	KEYWORD	`nonn,easy`
	AUTHOR	`Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Aug 09 2009`

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Last modified November 23 17:09 EST 2009. Contains 167438 sequences.

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