1233321

Appears in sequences

• a(n) = (10^n - 1)*(10^(2*n-1) - 1)/81.at n=2A053655
• All possible products in increasing order of two distinct members of the unary sequence 1, 11, 111, 1111, 11111, ...given by A000042.at n=11A077488
• Algebraic cofactor of n-th repunit A002275(n).at n=14A204848
• Pseudoprimes to base 5, written in base 5.at n=34A262102
• Numbers which are products of repunits.at n=21A308365
• Numbers that can be written as a product of distinct repunits.at n=13A334131