18713

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 85.at n=17A020424
• Number of 6 X 6 binary matrices with n ones, with no zero rows or columns, up to row and column permutation.at n=15A056037
• Irregular primes with irregularity index three.at n=29A060975
• Let f(x) = phi(x) + sigma(x); a(n) = least k such that at k begins a maximal run of length n of consecutive strict local extrema of f, or 0 if no such k exists.at n=28A066923
• Prime(n) and prime(n+2) use the same digits.at n=25A069794
• a(n) is the number of subsets of {1,...,n} containing no solutions to x+y=z with x and y distinct (one version of "sum-free subsets").at n=20A085489
• Primes congruent to 10 mod 59.at n=35A142737
• Primes congruent to 47 mod 61.at n=35A142845
• Antidiagonal sums of A145153.at n=16A145139
• a(n) = the smallest prime prime(k) such that prime(k+j) - prime(k+j-1) = prime(n+k+1-j) - prime(n+k-j) for all j with 1 <= j <= n.at n=3A175309
• Numbers k for which 6k+1, 24k+5, 432k^2+72k-1, and 432k^2+90k-1 are all prime.at n=22A175513
• Primes of the form k^2 + prime(k).at n=21A184935
• Monotonic ordering of set S generated by these rules: if x and y are in S and xy+1 is a prime, then xy+1 is in S, and 2, 5, 8, 11, and 14 are in S.at n=47A192585
• Primes of the form 3n^2 - 10.at n=12A201782
• Prime numbers > 10000 such that all the substrings of length >= 4 are primes (substrings with leading '0' are considered to be nonprime).at n=27A211686
• Number of -3..3 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having one, two, three, four or five distinct values for every i,j,k<=n.at n=7A211727
• Smallest of three consecutive primes whose average is a triangular number.at n=0A226150
• a(n) = prime(n*prime(n)).at n=23A228529
• Primes p such that p^7 + 2 is also prime.at n=39A261537
• Smallest prime starting a (nonsingular) symmetric n-tuplet of the shortest span (=A266511(n)).at n=4A266512