1302451

Appears in sequences

• Pseudoprimes to base 2 of the form 4k+3.at n=37A177884
• Poulet numbers of the form (6k+1)*(24k+1).at n=7A182123
• Strong pseudoprimes (base 2) that become prime when two is subtracted.at n=12A230483
• Strong pseudoprimes k to base 2 such that either k-2 or k+2 is prime.at n=16A230487
• Composite numbers n such that n == 3 (mod 8) and 2^((n-1)/2) == -1 (mod n).at n=2A244628
• Composite numbers k == 3 (mod 4) such that (1 + i)^k == 1 - i (mod k), where i = sqrt(-1).at n=10A270697
• The "non-residue" pseudoprimes: odd composite numbers n such that b(n)^((n-1)/2) == -1 (mod n), where base b(n) = A020649(n).at n=24A307767
• Fermat pseudoprimes to base 2 that are decagonal.at n=24A321870
• Odd composite numbers k such that 2^((k-1)/2) == -1 (mod k).at n=17A356638