30089

Properties

Appears in sequences

• The 23-step cycle reached for any initial value k less than 100000, after iterations of sopf(8x+1), where sopf(n) denote the sum of the prime factors of n (sopf(12) = 2+2+3 = 7).at n=16A071712
• Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[2, 6,6]; short d-string notation of pattern = [266].at n=11A078849
• Primes p such that the differences between the 5 consecutive primes starting with p are (2,6,6,6).at n=4A078951
• Primes P such that P and P+2 are twin primes and P = p(n)# + p(m) with p(n) < p(m) < p(n+1)^2, or 0 if no such prime P for n, p(n)# = n-th primorial, p(m)= m-th prime ( p(m), p(m+1) twin primes ).at n=13A088903
• Primes p such that p and p+2 are twin primes and also the strings 987654321p and 987654321p+2 are twin primes.at n=13A103818
• Primes from merging of 5 successive digits in decimal expansion of cos(1).at n=17A104961
• Primes dividing some member of A073833.at n=39A161500
• Primes p such that sigma(p+3) = sigma(p-3).at n=7A169596
• Eighth prime p such that (p+n)^2+n is prime but (p+j)^2+j is not prime for all 0<j<n.at n=20A238680
• Partial sums of primes, but with a twist.at n=18A247657
• P(n,k) is an array read by rows, with n > 0 and k=1..5, where row n gives the chain of 5 consecutive primes {p(i), p(i+1), p(i+2), p(i+3), p(i+4)} having the symmetrical property p(i) + p(i+4) = p(i+1) + p(i+3) = 2*p(i+2) for some index i.at n=19A267028
• Least prime p such that p^n + 1 is the product of n distinct primes.at n=12A280005
• Least k such that k^n + 1 is the product of n distinct primes (k > 0).at n=12A281940
• Number of nX5 0..1 arrays with every element equal to 0, 1, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.at n=5A299177
• Number of nX6 0..1 arrays with every element equal to 0, 1, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.at n=4A299178
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.at n=49A299180
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.at n=50A299180
• Primorial base emirps: prime numbers whose primorial base reversal is a different prime.at n=15A333425
• Least number k such that the sum of the n Moebius function values beginning at k reaches the minimum value -A083544(n).at n=10A343172
• Primes in A239237.at n=21A361252