19333

Properties

Appears in sequences

• a(0)=2; for n>=1, a(n) = smallest prime p such that there is a gap of exactly 2n between p and next prime, or -1 if no such prime exists.at n=20A000230
• Numbers k such that the continued fraction for sqrt(k) has period 97.at n=7A020436
• Primes that remain prime through 4 iterations of function f(x) = 2x + 5.at n=16A023304
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 16.at n=12A031604
• "DHK" (bracelet, identity, unlabeled) transform of 1,0,1,0,... (odd).at n=29A032243
• Sum{T(i,n-i): i=0,1,...,n}, array T as in A047040; Sum{T(i,n-i): i=0,1,...,n}, array T given by A047050.at n=16A047041
• Number of rooted trees with n nodes with every leaf at the same height.at n=22A048816
• Smallest prime larger than square of n-th prime.at n=33A062772
• Class 6+ primes.at n=23A081634
• a(n) is the smallest prime p of the form 4k+1 such that nextprime(p) - p = 4n.at n=9A082099
• Primes p such that (r-p)/log(p) > 4, where r is the next prime after p.at n=3A082889
• Primes p such that p's set of distinct digits is {1,3,9}.at n=33A108383
• prime(k) for those k where floor((2*(prime(k+1)-prime(k))*PrimePi(k) mod (8*k))/k) = m with m = 11.at n=7A109565
• a(0)=1, a(1)=1, a(n)=7*a(n/2) for n=2,4,6,..., a(n)=6*a((n-1)/2)+a((n+1)/2) for n=3,5,7,....at n=43A116522
• Primes p such that p+1, p+2 and p+3 have equal number of divisors.at n=23A119711
• Numbers appearing in A122072 at least four times.at n=8A122390
• Primes p such that q-p = 40, where q is the next prime after p.at n=0A126721
• Primes of the form k^2 + 12.at n=22A138368
• First occurrence of prime gap 10*n.at n=3A140791
• Primes congruent to 40 mod 59.at n=34A142767