19139

Properties

Appears in sequences

• Apply partial sum operator thrice to binary rooted tree numbers.at n=14A014169
• Let (p1,p2), (p3,p4) be pairs of twin primes with p1*p2=p3+p4-1; sequence gives values of p1.at n=21A047976
• p(n+1) is next smallest prime beginning with p(n), initial prime is 19.at n=3A048556
• Numerators of b(n) = (1/16^n)*(4/(8*n+1) - 2/(8*n+4) - 1/(8*n+5) - 1/(8*n+6)).at n=12A048581
• a(n) = T(n,n-6), array T as in A055801.at n=30A055806
• Geometric mean of the digits = 3. In other words, the product of the digits is = 3^k where k is the number of digits.at n=39A061427
• Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=28A075585
• Primes with at least four digits such that sum of any three_neighbor_digits is prime; first and last digits are neighbors.at n=39A086259
• Primes A005382(n) + A005384(n) - 1 with a twin prime A005382(n) + A005384(n) + 1.at n=26A099109
• Primes p such that p and p+2 are twin primes and also the strings 987654321p and 987654321p+2 are twin primes.at n=9A103818
• Primes p such that p + 2 and p*(p + 2) + 2 are primes.at n=36A108013
• Primes p such that p's set of distinct digits is {1,3,9}.at n=31A108383
• Number of inversions in all Fibonacci binary words of length n.at n=14A129707
• Lesser of twin primes isolated from neighboring primes by +- 10 (or more).at n=38A138063
• Primes congruent to 6 mod 53.at n=38A142536
• Primes congruent to 46 mod 61.at n=37A142844
• a(n) is the smallest prime divisor of (A177929(n)-1)*(A177929(n)+1).at n=75A177930
• Records in A177930.at n=12A177932
• Number of nondecreasing arrangements of 10 numbers in 0..n with the last equal to n and each after the second equal to the sum of one or two of the preceding four.at n=35A189333
• Primes p such that p+2 and q are primes, where q is concatenation of binary representations of p and p+2: q = p * 2^L + p+2, where L is the length of binary representation of p+2: L=A070939(p+2).at n=20A232238