26927

Properties

Appears in sequences

• Numbers k such that 10^k + 3 is prime.at n=20A049054
• Numbers n such that 103*2^n-1 is prime.at n=23A050577
• Frobenius number of the numerical semigroup generated by 3 consecutive triangular numbers.at n=30A069755
• Take A000040, omit commas: 23571113171923..., select 5-digit primes seen when scanning from left.at n=26A073038
• Odd primes p such that the number of primes less than p that are congruent to 1 (mod 4) is equal to the number of primes less than p that are congruent to 3 (mod 4).at n=10A096447
• Fixed points for prime number permutation A108546.at n=19A108547
• a(n) = 15 + floor((2 + Sum_{j=1..n-1} a(j))/3).at n=26A120159
• The sequence gives prime numbers formed from the sum of the squares of composite numbers and the corresponding prime numbers.at n=14A180233
• Primes of the form 6n^2 - 7.at n=25A201792
• Number of Dyck n-paths all of whose ascents and descents have lengths equal to 1 (mod 8).at n=34A212367
• Number of partitions of n such that m(2) < m(3), where m = multiplicity.at n=45A240063
• Primes of the form 11*n^2 + 55*n + 43.at n=36A292578
• a(n) is the least number which is coprime to its digital sum (A339076) with a gap n to the next term of A339076, or 0 if such a number does not exist.at n=11A339078
• Start from the sequence of primes, keep the 1st, then delete 2 primes, keep the next, delete 3 primes, keep the next, delete 5 primes, etc ...at n=39A350170
• Primes p such that q1=6*p-1 and q2=6*p+1 are also primes (twin primes) and q1 is a Sophie Germain prime (i.e., 2*q1+1 is prime).at n=22A358381
• Primes p such that 10^p+3 or 10^p+9 is also prime.at n=7A359630
• Expansion of Product_{k>=1} 1 / ((1 - x^k) * (1 - x^(k^3))).at n=29A369579
• Prime numbersat n=2954