1002000

Appears in sequences

• a(n) is the unique k such that palindrome A068065(n) = k + reverse(k).at n=19A068910
• a(n) = (10^n+1)^2 - 1.at n=3A134230
• a(n+1) is the least integer > a(n) containing all digits of a(n); a(1)=2.at n=34A155890
• Sum of any three adjacent digits of n^2 is a square.at n=51A174397
• In base 3, 0, together with numbers of the form i00j00k00m00... where i = 1 or 2 and j,k,m,... are 0, 1, or 2.at n=31A261660