1,1

a(n) = 6*5^((n-1)/2)-2 (n odd), 2*5^(n/2)-2 (n even).

Cf. A050250.

Sequence in context: A110132 A099513 A104042 this_sequence A020138 A090083 A034515

Adjacent sequences: A117861 A117862 A117863 this_sequence A117865 A117866 A117867

nonn

Martin Renner (martin.renner(AT)gmx.net), May 02 2006