A080043 - OEIS

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A080043

a(n)=floor((2+sqrt(7))^n).

1, 4, 21, 100, 465, 2164, 10053, 46708, 216993, 1008100, 4683381, 21757828, 101081457, 469599316, 2181641637, 10135364500, 47086382913, 218751625156, 1016265649365, 4721317472932, 21934066839825, 101900219778100 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	FORMULA	`G.f.: g(t)=(1+t^2+4t^3)/(1-4t-4t^2+4t^3+3t^4) a(n)=A080042(n)-(1+(-1)^n)/2`
	MATHEMATICA	`CoefficientList[Series[(1+t^2+4t^3)/(1-4t-4t^2+4t^3+3t^4), {t, 0, 25}], t]`
	CROSSREFS	`Sequence in context: A174797 A017967 A076901 * A113022 A014986 A015531` `Adjacent sequences: A080040 A080041 A080042 * A080044 A080045 A080046`
	KEYWORD	`easy,nonn`
	AUTHOR	`Mario Catalani (mario.catalani(AT)unito.it), Jan 21 2003`

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Last modified February 16 04:47 EST 2012. Contains 205860 sequences.