OFFSET
1,2
COMMENTS
The differences of {a(n)}, together with a conjectured formula for them, is given in A114890.
EXAMPLE
Given that a(1)=1, a(2)=3 and a(3)=4, we find that a(4)>5 since 5+4=9 and a(4)>6 since 6+3=9. But none of 7+1, 7+3, or 7+4 is a power of 3, so a(4)=7.
CROSSREFS
KEYWORD
nonn
AUTHOR
John W. Layman, Jan 04 2006
STATUS
approved