18833

Appears in sequences

• Denominators of continued fraction convergents to sqrt(550).at n=10A042053
• Reverse of smallest prime factor of k = largest prime factor of k+1; a(1)=1.at n=20A071392
• Number of positive words of length n in the monoid Br_9 of positive braids on 10 strands.at n=6A097556
• Number of 2Xn 0..1 arrays with row sums nondecreasing and column sums unimodal.at n=9A223626
• Numbers n that have record value of prime p such that p + 2n is another prime.at n=14A239392
• Number of length 2+3 0..n arrays with some disjoint pairs in every consecutive four terms having the same sum.at n=15A247534
• Sum of lcm(gcd(i,j), gcd(k,l)) for i,j,k,l in range [1..n].at n=8A260842
• a(n) is the least k such that gcd(A006666(k), A006667(k)) = n.at n=34A281938
• Numbers k such that k!4 + 2^4 is prime, where k!4 = k!!!! is the quadruple factorial number (A007662).at n=32A291344
• Positions of records in A204911.at n=17A317249
• 2*a(n) = m is the least even number m such that all sums m + prime(k), k=1..n are composite.at n=37A370998
• 2*a(n) = m is the least even number m such that all sums m + prime(k), k=1..n are composite.at n=38A370998
• 2*a(n) = m is the least even number m such that all sums m + prime(k), k=1..n are composite.at n=39A370998
• 2*a(n) = m is the least even number m such that all sums m + prime(k), k=1..n are composite.at n=40A370998
• One half of the even Markoff nunbers.at n=6A388289
• Expansion of g/(1 - x^4*g^3), where g = 1+x*g^2 is the g.f. of A000108.at n=10A391034