OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
FORMULA
a(n)/n has the limit 1/(1-Log[9]/Log[10]) = 21.85434... - Stefan Steinerberger, Dec 12 2007
MATHEMATICA
Select[Range[1115], Length[IntegerDigits[9^# ]] == Length[IntegerDigits[9^#*9]] &] (* Stefan Steinerberger, Dec 12 2007 *)
PROG
(PARI) isok(n) = #digits(9^n) == #digits(9^(n+1)); \\ Michel Marcus, Oct 12 2016
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Dec 11 2007
STATUS
approved