0,3

O.g.f.: -x/(-1+4*x+7*x^2). a(n)=-7^n*(A^n-B^n)/(2sqrt(11)) where A=-1/(2+sqrt(11)) and B=1/(sqrt(11)-2) . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 29 2008

Sequence in context: A082970 A017973 A124507 this_sequence A024050 A038723 A091640

Adjacent sequences: A015529 A015530 A015531 this_sequence A015533 A015534 A015535

nonn,easy

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