129921

Appears in sequences

• Composite numbers k such that k == +-1 (mod 8) and 2^((k-1)/2) == 1 (mod k).at n=34A006971
• Strong pseudoprimes to base 4.at n=33A020230
• Palindromic pseudoprimes (base 2).at n=1A068445
• Antidiagonal sums of square array A082011.at n=32A082014
• Pseudotwinprimes p+2 for primes p such that p+2 divides p^(p+2)+2 and p+2 is composite.at n=32A100873
• Pseudoquadprimes: p+4 for primes p where p+4 divides p^(p+4) + 4 and p+4 is composite.at n=15A100875
• Pseudoprimes (base-2) equal to product of 4 primes not necessarily distinct.at n=13A112441
• Pseudoprimes divisible by a smaller pseudoprime.at n=9A215150
• Pseudoprimes n to base 2 such that n-2 and n-4 are primes.at n=2A230488
• Composite numbers k == 1 (mod 4) such that (1 + i)^k == 1 + i (mod k), where i = sqrt(-1).at n=37A270698
• Square array A(n, k) read by antidiagonals downwards: smallest base-n strong Fermat pseudoprime with k distinct prime factors for k, n >= 2.at n=12A360184
• Smallest base-n strong Fermat pseudoprime with n distinct prime factors.at n=2A361256
• Fermat pseudoprimes to base 2 that are products of two Mersenne numbers (not necessarily distinct) that are larger than 1.at n=2A367229