250867

Properties

Appears in sequences

• Expansion of e.g.f. exp(x) * (sec(exp(x) - 1))^2.at n=8A080832
• Number of n X n binary arrays with all ones connected only in a 1000-1111-0001 pattern in any orientation.at n=8A146602
• Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1111-0001 pattern in any orientation.at n=18A146604
• Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1111-0001 pattern in any orientation.at n=19A146604
• Primes prime(k) such that 2^(k+1) + prime(k) is also prime.at n=16A244916
• Prime numbersat n=22105