0,3

O.g.f.: -x/(-1+4*x+9*x^2). a(n)=-9^n*(A^n-B^n)/(2sqrt(13)) where A=-1/(2+sqrt(13)) and B=1/(sqrt(13)-2) . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 29 2008

Sequence in context: A069639 A013582 A123660 this_sequence A079291 A072221 A055846

Adjacent sequences: A015530 A015531 A015532 this_sequence A015534 A015535 A015536

nonn,easy

Olivier Gerard (ogerard(AT)ext.jussieu.fr)