227387

Properties

Appears in sequences

• Primes that cannot become a different prime under any mapping of some single decimal digit <=> with some other single decimal digit.at n=31A180561
• a(1) = a(2) = 1; a(n+2) = 1 + Sum_{d|n} a(n/d) * a(d).at n=34A346116
• Absolute discriminants of imaginary quadratic number fields with elementary bicyclic 7-class group (7,7).at n=10A359872
• Prime numbersat n=20210