0,6

G.f.: -1/5-1/4/(t-1)-1/20/(3*t-1)+1/5/(2*t+1)+3/10/(5*t^2-1). a(n)=(5+3^n+(-1)^n*2^(n+2)-3*(1+(-1)^n)*sqrt(5)^n)/20 for n>0.

Sequence in context: A107904 A071930 A061520 this_sequence A005402 A128953 A002898

Adjacent sequences: A054880 A054881 A054882 this_sequence A054884 A054885 A054886

nonn

Paolo Dominici (pl.dm(AT)libero.it), May 23 2000