id:A084778 - OEIS Search Results

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a(n) = sum of absolute-valued coefficients of (1+2x-3x^2)^n.

+0
1

1, 6, 28, 128, 660, 3016, 13108, 64112, 304068, 1332992, 6514356, 29341384, 131904528, 623547112, 2990903464, 13436119424, 61647598484, 284398511848, 1302463169256, 6195158123688, 28653898573420, 130138400720504 (list; graph; listen)

	OFFSET	`0,2`
	PROGRAM	`(PARI) for(n=0, 40, S=sum(k=0, 2n, abs(polcoeff((1+2x-3*x^2)^n, k, x))); print1(S", "))`
	CROSSREFS	`Sequence in context: A026851 A002693 A117423 this_sequence A108051 A001599 A074247` `Adjacent sequences: A084775 A084776 A084777 this_sequence A084779 A084780 A084781`
	KEYWORD	`nonn`
	AUTHOR	`Paul D. Hanna (pauldhanna(AT)juno.com), Jun 14 2003`

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Last modified December 2 15:58 EST 2008. Contains 150992 sequences.

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