18133

Properties

Appears in sequences

• Reflectable emirps.at n=21A007628
• s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (odd natural numbers), t = A001950 (upper Wythoff sequence).at n=33A025114
• a(1)=2; a(n) for n>1 is the smallest prime number > a(n-1) such that the concatenation of all previous terms is also prime.at n=31A080155
• Primes congruent to 7 mod 53.at n=40A142537
• Primes congruent to 20 mod 59.at n=36A142747
• Primes congruent to 16 mod 61.at n=31A142814
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, 1, 1), (1, -1, -1), (1, 0, -1)}.at n=9A148832
• Smallest emirp corresponding to the prime of A178581.at n=24A178582
• Smallest emirp corresponding to A178585.at n=16A178586
• Primes p such that p plus or minus the sum of its digits squared yields a prime in both cases.at n=39A179550
• Primes that are the sum of three consecutive primes in A034962.at n=27A207527
• Primes p for which exactly five bases b with 1 < b < p exist such that p is a base b Wieferich prime.at n=6A255208
• a(n) is the largest number such that every subsequence of digits of the number written in base n is prime.at n=25A282509
• Greatest of 4 consecutive primes with consecutive gaps 6, 4, 2.at n=23A290635
• Primes p such that p^4 - 1 has 160 divisors.at n=38A341662
• Emirps p such that (p*q) mod (p+q) is also an emirp, where q is the digit reversal of p.at n=31A355651
• a(n) is the number of n-digit numbers whose difference between the largest and smallest digits is equal to 3.at n=5A367244
• Expansion of Product_{i>=1, j>=0} (1 + x^(i * 5^j)).at n=55A373219
• Primes having only {1, 3, 8} as digits.at n=41A385778
• Maximum word length generated by acyclic context-free grammar in Greibach normal form whose grammar size is at most n.at n=34A389642