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Search: id:A006646
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A006646 Exponential self-convolution of Pell numbers. +0
3
0, 0, 2, 12, 64, 320, 1568, 7616, 36864, 178176, 860672, 4156416, 20070400, 96911360, 467935232, 2259402752, 10909384704, 52675215360, 254338531328, 1228055248896, 5929575645184, 28630524624896 (list; graph; listen)
OFFSET

0,3

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

CROSSREFS

Cf. A000129.

Adjacent sequences: A006643 A006644 A006645 this_sequence A006647 A006648 A006649

Sequence in context: A121177 A125831 A026076 this_sequence A087635 A052896 A025599

KEYWORD

nonn

AUTHOR

njas

page 1

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Last modified October 12 15:26 EDT 2008. Contains 144830 sequences.


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