19379

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of function f(x) = 10x + 3.at n=42A023300
• Primes that remain prime through 4 iterations of function f(x) = 10x + 3.at n=5A023328
• Numbers k such that 287*2^k + 1 is a prime.at n=8A053360
• Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=29A075585
• Safe primes (A005385) (p and (p-1)/2 are primes) such that 12*p+1 is also prime.at n=45A075707
• Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[2,6,4]; short d-string notation of pattern = [264].at n=23A078848
• Primes of the form prime(2k) followed by prime(k).at n=5A089786
• Primes of the form 6n^2 - 2n - 1.at n=20A099007
• Number of distinct products i*j*k*l for 1 <= i < j < k < l <= n.at n=40A100438
• Primes p such that p + 2 and p*(p + 2) + 2 are primes.at n=37A108013
• Primes p such that p's set of distinct digits is {1,3,7,9}.at n=13A108386
• Primes p such that 6p + 7 is a square.at n=42A110014
• Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k base pyramids.at n=57A129165
• Primes congruent to 42 mod 61.at n=33A142840
• The 4k+3 integers corresponding to the record positions in A165601.at n=40A166046
• Primes p of the form a^2-b^2 and p*a-b is also prime (with b=prime and a=b+1).at n=17A173875
• Primes with eight embedded primes.at n=9A179916
• Number of 4-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=31A187509
• Number of lower triangles of an n X n 0..4 array with no element differing from any of its horizontal or vertical neighbors by more than one.at n=3A194927
• T(n,k)=Number of lower triangles of an n X n 0..k array with no element differing from any of its horizontal or vertical neighbors by more than one.at n=24A194931