a(9) = 5 is the number of letters in "Pluto", considered a planet when this sequence was submitted. - Charles R Greathouse IV, Jan 16 2016
Table of n, a(n) for n=1..9.
The Nine Planets, Perfect Numbers
Sequence in context: A152115 A098842 A173166 * A158244 A226580 A182007
Adjacent sequences: A070270 A070271 A070272 * A070274 A070275 A070276
Wade McBeth (c_o_n_n_o_r(AT)hotmail.com), May 12 2002