138239

Properties

Appears in sequences

• a(n) is smallest prime such that a(n)+1 is a proper multiple of a(n-1)+1 [with a(1)=1].at n=10A058000
• Primes p such that 5 is the largest of all prime factors of the numbers between p and the next prime (cf. A052248).at n=19A080185
• Primes arising in A084402. a(n) = n-th partial product of A084402 - 1.at n=10A084403
• Smaller member of a twin prime pair such that the sum sets a record for number of prime divisors (counted with multiplicity).at n=8A086827
• Numbers k such that A109631(k) - A109631(k+1) = A109631(k+2).at n=34A109715
• a(1)=2. For n >= 2, a(n) = a(n-1) + 1 + (the largest prime among the first n-1 terms of the sequence {a(k)}).at n=22A133489
• a(n) is the number of numbers removed in each step of Eratosthenes's sieve for 10!.at n=3A145537
• a(n) = p is the first twin prime (p, p+2) for which p+1 has n prime factors (n>=2, multiplicity counted).at n=12A164291
• Sums of pairs of betrothed (or quasi-amicable) numbers.at n=8A179612
• Primes of the form 10n^3-1.at n=7A201036
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 453", based on the 5-celled von Neumann neighborhood.at n=19A288368
• Primes of the form p*q+r*s+t*u, where p,q,r,s,t,u are consecutive primes.at n=7A340464
• Primes of the form prime(i)*prime(i+1)+prime(i+2)*prime(i+3)+...+prime(k-1)*prime(k).at n=28A340465
• Prime numbersat n=12861