28019

Properties

Appears in sequences

• Primes whose digits can be arranged in increasing cyclic order - to form a substring of 123456789012345678901234567890...at n=40A068710
• Primes p2 such that p1^3 + p2^2 is an average of twin primes and p1 < p2 are consecutive primes.at n=20A138755
• Greater of two consecutive primes, p < q, such that both p*q+p-q and p*q-p+q are prime numbers.at n=34A154552
• Primes p of the form a^2-b^2 and p*a-b is also prime (with b=prime and a=b+1).at n=20A173875
• Cyclops Sophie-Germain primes.at n=14A183058
• Cyclops primes p such that 2p+1 is also a Cyclops prime.at n=6A183059
• Primes p such that 16*p^2 + 10*p + 1 divides 2^p - 1.at n=11A231916
• Number of times prime(n) occurs as the least prime factor among numbers 1 .. prime(n)^4: a(n) = A078898(A030514(n)).at n=16A250478
• Number of essentially series nonequivalent series-parallel networks with n elements and without unit elements in parallel.at n=18A339151
• Primes p whose reverse q is a semiprime, and of p+q and its reverse one is a prime and the other is a semiprime.at n=38A350781
• Integers k such that 28*phi(29*197^3*k) is not a totient number where phi is the totient function.at n=9A361396
• Records in A030000.at n=45A372044
• Prime numbersat n=3057