18149

Properties

Appears in sequences

• Supersingular primes of the elliptic curve X_0 (11).at n=21A006962
• Numbers k such that the continued fraction for sqrt(k) has period 41.at n=35A020380
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (composite numbers), t = (odd natural numbers).at n=37A025104
• Lower prime of a difference of 20 between consecutive primes.at n=35A031938
• Numbers k such that s(k) + s(k+1) + ... + s(k+14) = t(k) + t(k+1) + ... + t(k+14).at n=4A033916
• Numbers whose base-5 representation contains exactly three 0's and three 4's.at n=14A045217
• Primes resulting from procedure described in A048388.at n=31A048389
• a(n) = Sum_{i=0..n} T(i,n-i), array T as in A049735.at n=20A049736
• First term of strong prime quintets: p(m+1)-p(m) > p(m+2)-p(m+1) > p(m+3)-p(m+2) > p(m+4)-p(m+3).at n=41A054808
• Primes of the form 6n^2 - 1.at n=21A090686
• Primes p whose period of reciprocal equals (p-1)/13.at n=2A098680
• Number of benzenoids with 21 hexagons with C_(2v) symmetry containing n carbon atoms.at n=16A121983
• Primes of the form 2*3*5*7*k+89, k >= 0.at n=39A141866
• Primes congruent to 23 mod 53.at n=37A142553
• Primes congruent to 36 mod 59.at n=31A142763
• Primes congruent to 32 mod 61.at n=31A142830
• Primes p such that both pi(p) and the concatenation of pi(p) and p are prime, where pi is the prime counting function.at n=32A155032
• Primes of the form m*(m+1)/2 + 4.at n=31A159048
• Number of permutations of 1..n containing the relative rank sequence { 124653 } at any spacing.at n=3A159085
• Number of permutations of 1..n containing the relative rank sequence { 126435 } at any spacing.at n=3A159087