100020000

Appears in sequences

• a(n) is the unique k such that palindrome A068065(n) = k + reverse(k).at n=25A068910
• a(n) = (10^n+1)^2 - 1.at n=4A134230
• Concatenate the positions of digits 0, 1, ..., 9 in the decimal representation of n, using 1 for the leftmost digit etc., and 0 when the digit does not occur.at n=15A260520