OFFSET
3,1
COMMENTS
Second differences of (a(3k), a(3k + 1), a(3k + 1)) and (a(3k + 1), a(3k + 2), a(3k + 3)) appear to be 48 * 9^(k - 1). Based on this conjecture, we would have a(15) = 306435. - David A. Corneth, Apr 15 2015
CROSSREFS
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Sep 30 2008
STATUS
approved