253241

Appears in sequences

• Strong pseudoprimes to base 2.at n=22A001262
• Numbers n such that game of n X n Button Madness need have no solution; this lists only the primitive elements of the set.at n=22A007802
• Sarrus numbers that become prime when two is added.at n=13A137198
• Overpseudoprimes to base 2: composite k such that k = A137576((k-1)/2).at n=11A141232
• Numbers k (between 2^(m-1) and 2^m) such that 2^(k-1) == 1 (mod k) and 2^(k-1-m) == k - 2^p (mod k) for some p > 0 with 2^p < k.at n=23A167612
• Lesser of overpseudo-twin-primes to base 2 defined in Comment.at n=2A195468
• Pseudoprimes to a twin prime criterion of Aebi and Cairns.at n=14A224695
• Strong pseudoprimes (base 2) that become prime when two is added.at n=0A230484
• Strong pseudoprimes k to base 2 such that either k-2 or k+2 is prime.at n=8A230487
• Numbers k > 1 such that 2^k == 2 (mod k) and gcd(k, 3^k - 3) = 1.at n=8A300762
• Numbers k such that 2^(k-1) == 1 (mod k) and lpf(k)-1 does not divide k-1.at n=14A316906
• Numbers k such that 2^(k-1) == 1 (mod k) and p-1 does not divide k-1 for every prime p dividing k.at n=12A316907