1,1
a(n) = 8*7^((n-1)/2)-2 (n odd), 2*7^(n/2)-2 (n even).
Cf. A050250.
Sequence in context: A106692 A032470 A018809 * A094060 A076722 A076305
Adjacent sequences: A117863 A117864 A117865 * A117867 A117868 A117869
nonn,base
Martin Renner (martin.renner(AT)gmx.net), May 02 2006