A133993 - OEIS

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A133993

a(n)=a(n-1)+3a(n-2)-a(n-3)-2a(n-4), n > 3.

1, 2, 3, 4, 9, 14, 31, 56, 117, 226, 459, 908, 1825, 3638 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	LINKS	`Index to sequences with linear recurrences with constant coefficients, signature (1,3,-1,-2).`
	FORMULA	`a(n) = 1+42^n/9+(-1)^n(n/3-4/9).` `G.f.: ( 1+x-2x^2-4x^3 ) / ( (2x-1)(x-1)*(1+x)^2 ).`
	CROSSREFS	`Sequence in context: A181287 A082981 A077906 * A122974 A032982 A033076` `Adjacent sequences: A133990 A133991 A133992 * A133994 A133995 A133996`
	KEYWORD	`nonn,easy`
	AUTHOR	`Paul Curtz (bpcrtz(AT)free.fr), Jan 22 2008`

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Last modified February 15 23:53 EST 2012. Contains 205860 sequences.