OFFSET
1,2
COMMENTS
Apart from the first term, identical to A089226. - R. J. Mathar, May 31 2008
EXAMPLE
a(10) = 1023 because 1023 base 2 = 1111111111 which has 10 1's and 1023 = 3 * 11 * 31 is nonprime.
CROSSREFS
KEYWORD
easy,base,nonn
AUTHOR
Jonathan Vos Post, May 26 2008
EXTENSIONS
More terms from R. J. Mathar, May 31 2008
STATUS
approved