18199

Properties

Appears in sequences

• Number of step cyclic shifted sequence structures using a maximum of four different symbols.at n=12A056431
• Numbers k such that 11^k - 10^k is prime.at n=8A062577
• Fixed points when A001414 is iterated and started at factorials of prime numbers.at n=65A082086
• Primes of the form (prime(prime(k)) + prime(prime(k+1)))/2.at n=17A098042
• Primes of the form 55x^2+10xy+199y^2.at n=35A140632
• Primes congruent to 20 mod 53.at n=39A142550
• Primes congruent to 27 mod 59.at n=38A142754
• Primes congruent to 21 mod 61.at n=35A142819
• Lesser of two consecutive primes, p < q, such that both p*q+p-q and p*q-p+q are prime numbers.at n=26A154553
• Expansion of x*(x+1) / (x^2-26*x+1).at n=3A157461
• Number of permutations of 1..n containing the relative rank sequence { 136254 } at any spacing.at n=3A159104
• Primes p such that p-1 and p+1 each contain at least one cubed prime in their prime factorization.at n=25A162870
• Primes p that p//13 and p//31 are consecutive primes.at n=26A176601
• Odd primes which can never divide 2^a+2^b+1.at n=29A179113
• First of a run of 4 or more consecutive primes which all equal 1 (mod 3).at n=38A185942
• Primes of the form 7n^2 - 8.at n=7A201853
• Lesser of two consecutive primes, p < q, such that p*q + p - q and p*q - p + q are also consecutive primes.at n=14A225726
• Primes p such that p + 4, p + 16, p + 64, p + 256 and p + 1024 are all semiprimes.at n=18A241493
• Primes p such that 2*p+1 is divisible by the sum of digits of p+1.at n=31A267542
• a(1) = 2; a(n + 1) = smallest prime > a(n) such that a(n + 1) - a(n) is the product of 7 primes.at n=29A285692