1,1

a(n) = 10*9^((n-1)/2)-2 (n odd), 2*9^(n/2)-2 (n even).

Cf. A050250.

Sequence in context: A089828 A082982 A131539 this_sequence A062508 A083086 A080452

Adjacent sequences: A117865 A117866 A117867 this_sequence A117869 A117870 A117871

nonn

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