19553

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 85.at n=18A020424
• a(i) is a square mod a(j), i <> j; a(n) prime; a(1) = 2.at n=8A034902
• Primes with all odd digits such that the next three primes also contain all odd digits.at n=17A068831
• a(n) = p - A072181(n), where p is the least prime > A072181(n) + 1.at n=42A082432
• Smallest prime a such that (a*b)^2 + a*b -1 is prime with b prime = 2^(2*n) - 2^n - 1, see A098845 for n.at n=27A107639
• Moessner triangle based on primes.at n=24A125312
• Primes p such that q = p+d (with d >= 6) is the next prime and both p and q are Sophie Germain primes.at n=32A128825
• Primes congruent to 24 mod 59.at n=34A142751
• Primes congruent to 33 mod 61.at n=38A142831
• Partial sums of Iccanobif numbers A001129.at n=14A172524
• a(n) = 6*b_6(n)+5, where b_6 lists the indices of zeros of the sequence A261306: u(n) = abs(u(n-1)-gcd(u(n-1),6*n-1)), u(1) = 1.at n=4A186258
• Number of ordered triples (w,x,y) with all terms in {-n, ..., -1, 1, ..., n} and 5w + x + y > 0.at n=17A211630
• Number of (n+1) X 7 0..2 matrices with each 2 X 2 subblock idempotent.at n=12A224674
• Primes whose base-7 representation also is the base-3 representation of a prime.at n=22A235470
• Non-palindromic balanced primes.at n=38A256076
• a(1) = 2; for n > 1, a(n) is the least prime p not already in the sequence such that the Hamming distance between p and a(n-1) is 1.at n=17A294205
• Numbers at the start of a run of 2 or more consecutive primes that are Sophie Germain primes.at n=33A339474
• Numbers at the start of a run of exactly 2 consecutive primes that are Sophie Germain primes.at n=32A339475
• First of four consecutive primes p,q,r,s such that p+q+r+s is divisible by A001414(q+r).at n=51A352480
• Primes p such that p+1 is a triprime and 2*p+1 is prime.at n=34A386295