0,4

a(2n+1)= a(2n+2)= A083420(n).

a(n+1)-2a(n) = (-1)^n*A014551(n), n>0.

a(n+1)-2a(n)-1 = 2*(-1)^n*A131577(n).

O.g.f.: x(1+2x^2)/((2x-1)(1+2x)(x-1)). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 02 2008

Adjacent sequences: A140249 A140250 A140251 this_sequence A140253 A140254 A140255

Sequence in context: A114369 A027844 A111217 this_sequence A095343 A121210 A112685

nonn

Paul Curtz (bpcrtz(AT)free.fr), Jun 23 2008

Edited and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 02 2008