%I A117864
%S A117864 4,8,28,48,148,248,748,1248,3748,6248
%N A117864 Number of palindromes (in base 5) below 5^n.
%F A117864 a(n) = 6*5^((n-1)/2)-2 (n odd), 2*5^(n/2)-2 (n even).
%Y A117864 Cf. A050250.
%Y A117864 Sequence in context: A110132 A099513 A104042 this_sequence A020138 A090083 
               A034515
%Y A117864 Adjacent sequences: A117861 A117862 A117863 this_sequence A117865 A117866 
               A117867
%K A117864 nonn
%O A117864 1,1
%A A117864 Martin Renner (martin.renner(AT)gmx.net), May 02 2006