21474181

Appears in sequences

• Poulet numbers (2-pseudoprimes) of the form 7200*n^2 + 8820*n + 2701.at n=23A214016
• Fermat pseudoprimes to base 2 that can be written as 2*p^2 - p, where p is also a Fermat pseudoprime to base 2.at n=3A215343
• Fermat pseudoprimes to base 2 that can be written as p^2*n - p*n + p, where p is also a Fermat pseudoprime to base 2 and n is a positive integer.at n=12A217835
• Numbers n such that n and n-1 are both nontrivial binomial coefficients.at n=14A298472