%I A049681
%S A049681 0,1,2,7,20,56,152,407,1080,2851,7502,19702,51680,135461,354902,929567,
%T A049681 2434320,6374236,16689752,43697227,114405500,299525051,784179002,
%U A049681 2053027082,5374926720,14071792681
%N A049681 a(n)=(L(2n)-L(n))/2, where L=A000032 (the Lucas sequence).
%Y A049681 Sequence in context: A018033 A000149 A080041 this_sequence A027120 A094982 
               A007460
%Y A049681 Adjacent sequences: A049678 A049679 A049680 this_sequence A049682 A049683 
               A049684
%K A049681 nonn
%O A049681 0,3
%A A049681 Clark Kimberling (ck6(AT)evansville.edu)
%E A049681 Corrected by Franklin T. Adams-Watters, Oct 25 2006
%E A049681 Corrected by T. D. Noe (noe(AT)sspectra.com), Nov 01 2006