0,3

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

Cf. A000129.

Sequence in context: A121177 A125831 A026076 this_sequence A087635 A052896 A025599

Adjacent sequences: A006643 A006644 A006645 this_sequence A006647 A006648 A006649

nonn

N. J. A. Sloane (njas(AT)research.att.com).