12327121

Appears in sequences

• Composite numbers j such that binomial(2*j,j) == 2^j (mod j).at n=11A084699
• Pseudoprimes to base 2 that are not squarefree, including the even pseudoprimes.at n=1A158358
• Catalan pseudoprimes: odd composite integers n=2*m+1 satisfying A000108(m) == (-1)^m * 2 (mod n).at n=2A163209
• Pseudoprimes to base 2 divisible by 3511^2, including the even pseudoprimes.at n=0A247831
• Numbers n > 1 where all prime factors are Wieferich primes, i.e., terms of A001220.at n=4A270833
• Composite numbers k such that D(k) == 3 (mod k), where D(k) is the k-th central Delannoy number (A001850).at n=15A330203
• Composite numbers k such that 2^(2^(k-1)-1) == 1 (mod k^2).at n=20A376253
• Strong pseudoprimes to base 2 that are not squarefree.at n=1A376304
• Composite numbers k such that binomial(4*k, k) == 4^k (mod k).at n=24A390043