%I A138495
%S A138495 0,1,1,1,3,9,15,25,55,121,231,441,903,1829,3655,7225,14535,29241,58311,
%T A138495 116281,232903
%N A138495 First differences of A138477.
%F A138495 O.g.f.: x/((1-2x)(1+x)(1+2x^2)) . a(n) = a(n-1) +2a(n-3) +4a(n-4). - 
               R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 19 2008
%F A138495 a(n)= -1/9*(-1)^n+2/9*2^n-1/18*(I*sqrt(2))^n-(1/9*I)*(I*sqrt(2))^n*sqrt(2)+(1/
               9*I) *sqrt(2)*(-I*sqrt(2))^n-1/18*(-I*sqrt(2))^n, with n>=0 and I=sqrt(-1) 
               - Paolo P. Lava (ppl(AT)spl.at), Jun 03 2008
%Y A138495 Sequence in context: A026222 A099989 A085046 this_sequence A055927 A087031 
               A089632
%Y A138495 Adjacent sequences: A138492 A138493 A138494 this_sequence A138496 A138497 
               A138498
%K A138495 nonn
%O A138495 0,5
%A A138495 Paul Curtz (bpcrtz(AT)free.fr), May 18 2008