OFFSET
1,1
FORMULA
The following inequality obviously holds for n > 1: a(n) >= (n-1)*10^(floor(1+log n) + floor(1+log(n+1))) + n*10^(floor(1+log(n+1))) + n + 1 where log is taken base 10, not base e. - Sam Alexander, Oct 19 2003
EXAMPLE
a(1) = 12 = 012, a(9) = 8910, a(13) = 1213147, 13 is sandwiched between 12 and 14.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 26 2002
EXTENSIONS
Corrected and extended by Sam Alexander, Oct 19 2003
STATUS
approved