OFFSET
1,2
COMMENTS
r(n) = 1, 4, 5, 12, 13, 17, 20, 21, 29, 36, 53, 60, 68, 76, 85, 92, 93,...
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Jul 27 2010
EXTENSIONS
Values a(2)-a(9) corrected, a(10) etc added by R. J. Mathar, Nov 04 2010
STATUS
approved