78401

Properties

Appears in sequences

• Primes of the form 2^a * 5^b * 7^c + 1 for positive a, b, c.at n=15A114992
• Numerator of Sum_{k=1..n} 1/(prime(k) - 1)^2.at n=6A119686
• Primes associated with A127435.at n=19A127436
• Primes p of Erdos-Selfridge class 5+ with largest prime factor of p+1 not of class 4+.at n=17A129473
• a(n) = 64*n^2 + 1.at n=35A158686
• The smallest prime p such that tau(p-1) + tau(p+1) = prime(n), or 0 if no such prime exists; where tau(k) is the number of divisors of k.at n=21A189536
• Primes of the form 8n^2 - 7.at n=23A201858
• A239459(n) / n.at n=27A239462
• First of two consecutive (primes of the form n^2+1) with no semiprime of the same form between them.at n=6A242109
• a(n+1) is the smallest prime > a(n) such that the digits of a(n) are all (with multiplicity) contained in the digits of a(n+1), with a(1)=7.at n=15A242907
• Primes in A258974.at n=33A258977
• a(n) = 1 + 100*n^2 for n >= 0.at n=28A323178
• Smallest prime p == 1 (mod 8) such that Q(sqrt(p)) has class number 2n+1.at n=23A355876
• Smallest p == 1 (mod 4) such that Q(sqrt(p)) has class number 2n+1.at n=23A355878
• Prime numbersat n=7695