Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
There are infinitely many nonzero squares in this sequence; for example a(10^(4n)-10^(2n)) = [10^n*(10^(2n)-1)]^2. - David Wasserman, Dec 07 2004
Table of n, a(n) for n=1..46.
a(n) = n*(10^d -1-n), where d is the number of digits in n.
a(n) = n*A061601(n). - David Wasserman, Dec 07 2004
Sequence in context: A235143 A179186 A192045 * A138666 A072835 A096229
Adjacent sequences: A084018 A084019 A084020 * A084022 A084023 A084024
Amarnath Murthy, May 23 2003
More terms from David Wasserman, Dec 07 2004