25224

Appears in sequences

• Number of primes less than 10000n.at n=28A038813
• Equal count of primes congruent to 1 mod 4 and 3 mod 4 associated with primes in A007351 (the zero beginning the sequence indicates the prime 2).at n=28A092198
• a(n) = 5*a(n-1) + 4*a(n-2) with a(0)=1, a(1)=4.at n=6A122690
• Triangle read by rows: T(n,k) = number of permutations p of 1,...,n, with min(|p(i)-p(i-1)|, i=2..n) = k (n>=2, k>=1).at n=28A129534
• Expansion of g.f.: 1/((1 - x - x^2 + x^4 - x^6)*(1 - x^2 + x^4 + x^5 - x^6)).at n=25A147606
• Numbers k such that 3^k + 100 is prime.at n=48A219618
• Records in A361902.at n=9A361997