OFFSET
0,3
COMMENTS
24th and 26th terms are unknown, but a(25)=9539, a(27)=4589 and a(28)=5960.
LINKS
Erich Friedman, Problem of the Month (Feb 2000)
FORMULA
a(n)=10^(n-2)+9, for n=2, 3, 4 and for n > 40.
EXAMPLE
a(5)=149 because 149 -(1)-> 513 -(2)-> 64 -(3)-> 10 -(4)-> 1 -(5)-> 0. a(7)=399 because 399 -(1)-> 1218 -(2)-> 339 -(3)-> 612 -(4)-> 73 -(5)-> 10 -(6)-> 1 -(7)-> 0.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Jason Earls, Apr 14 2001
EXTENSIONS
More terms from Berend Jan van der Zwaag, Jun 23 2001
STATUS
approved