87249

Appears in sequences

• Composite numbers k such that k == +-1 (mod 8) and 2^((k-1)/2) == 1 (mod k).at n=29A006971
• Euler-Jacobi pseudoprimes: 2^((n-1)/2) == (2 / n) mod n, where (2 / n) is a Jacobi symbol.at n=33A047713
• Sarrus numbers n (A001567) which satisfy mu(n) = -1 and which are not Super-Poulet numbers (A050217).at n=30A074380
• Sarrus numbers that become prime when two is added.at n=8A137198
• Lesser of pseudo twin primes to base 2.at n=37A192297
• Fermat pseudoprimes to base 2 with three prime factors.at n=30A215672
• Pseudoprimes to a twin prime criterion of Aebi and Cairns.at n=9A224695
• Pseudoprimes n to base 2 such that n+2 and n+4 are primes.at n=0A230489
• Smallest sets of 3 consecutive odd numbers that are primes or pseudoprimes (base 2). The initial odd number is listed.at n=6A230808
• Composite numbers k == 1 (mod 4) such that (1 + i)^k == 1 + i (mod k), where i = sqrt(-1).at n=31A270698
• Plumb pseudoprimes: odd composites that pass Colin Plumb's extended Euler criterion test.at n=26A288153
• a(1) = 0, a(2) = 1; and for n > 2, a(n) = 2*a(A285712(n)) + [1 == (n mod 3)].at n=30A292591