id:A020992 - OEIS Search Results

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A020992

a(n)=a(n-1)+a(n-2)+a(n-3).

+0
3

0, 2, 1, 3, 6, 10, 19, 35, 64, 118, 217, 399, 734, 1350, 2483, 4567, 8400, 15450, 28417, 52267, 96134, 176818, 325219, 598171, 1100208, 2023598, 3721977, 6845783, 12591358, 23159118, 42596259, 78346735, 144102112 (list; graph; listen)

	OFFSET	`0,2`
	FORMULA	`G.f.: x(2-x)/(1-x-x^2-x^3).` `a(n)=2*A000073(n+1)-A000073(n). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 22 2008]`
	CROSSREFS	`Sequence in context: A024866 A076058 A098124 this_sequence A025110 A075346 A104529` `Adjacent sequences: A020989 A020990 A020991 this_sequence A020993 A020994 A020995`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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