A099431 - OEIS

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A099431

Expansion of x(1-2x+3x^2)/(1-x-2x)^2;.

0, 1, 0, 6, 8, 30, 60, 154, 336, 774, 1700, 3762, 8184, 17758, 38220, 81930, 174752, 371382, 786420, 1660258, 3495240, 7340046, 15379100, 32156346, 67108848, 139810150, 290805060, 603979794, 1252698776, 2594876094, 5368709100 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,4`
	COMMENTS	`Convolution of A078008 and A099430(n-1)+3*0^n/2.`
	FORMULA	`a(n)=sum{k=0..n, (2^(n-k)+2(-1)^(n-k))/3(2^(k-1)-(-1)^k-1+30^k/20)}; a(n)=sum{k=0..n+1, A078008(n-k)binomial(n-k+1, k)binomial(1, (k+1)/2)(1-(-1)^k)/2}.`
	CROSSREFS	`Sequence in context: A000773 A039720 A056097 * A076904 A025091 A028321` `Adjacent sequences: A099428 A099429 A099430 * A099432 A099433 A099434`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Oct 15 2004`

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Last modified February 15 11:57 EST 2012. Contains 205782 sequences.