id:A087404 - OEIS Search Results

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a(n)=4a(n-1)+5a(n-2).

+0
2

2, 4, 26, 124, 626, 3124, 15626, 78124, 390626, 1953124, 9765626, 48828124, 244140626, 1220703124, 6103515626, 30517578124, 152587890626, 762939453124, 3814697265626, 19073486328124, 95367431640626, 476837158203124 (list; graph; listen)

	OFFSET	`0,1`
	FORMULA	`G.f.: (2-4x)/(1-4x-5x^2). a(n)=5^n+(-1)^n`
	MATHEMATICA	`CoefficientList[Series[(2 - 4x)/(1 - 4x - 5x^2), {x, 0, 25}], x]`
	CROSSREFS	`Sequence in context: A128774 A028386 A085700 this_sequence A009237 A019019 A032328` `Adjacent sequences: A087401 A087402 A087403 this_sequence A087405 A087406 A087407`
	KEYWORD	`easy,nonn`
	AUTHOR	`Mario Catalani (mario.catalani(AT)unito.it), Sep 01 2003`

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Last modified July 26 13:41 EDT 2008. Contains 142293 sequences.

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