A006646 - OEIS

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A006646

Exponential self-convolution of Pell numbers.

0, 0, 2, 12, 64, 320, 1568, 7616, 36864, 178176, 860672, 4156416, 20070400, 96911360, 467935232, 2259402752, 10909384704, 52675215360, 254338531328, 1228055248896, 5929575645184, 28630524624896 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	LINKS	`Vincenzo Librandi, Table of n, a(n) for n = 0..1000`
	FORMULA	`a(n)=((2+sqrt(8))^n+(2-sqrt(8))^n-2^(n+1))/8; E.g.f. : exp(2x)(sinh(sqrt(2)x))^2/2=(exp(x)sinh(sqrt(2)x)/sqrt(2))^2. - Paul Barry (pbarry(AT)wit.ie), May 16 2003`
	PROG	`(MAGMA) [Floor(((2+Sqrt(8))^n+(2-Sqrt(8))^n-2^(n+1))/8): n in [0..30] ]; // Vincenzo Librandi, Aug 20 2011`
	CROSSREFS	`Cf. A000129.` `Sequence in context: A121177 A125831 A026076 * A087635 A180038 A052896` `Adjacent sequences: A006643 A006644 A006645 * A006647 A006648 A006649`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`

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Last modified February 16 09:50 EST 2012. Contains 205904 sequences.