19469

Properties

Appears in sequences

• Indices of prime Lucas numbers.at n=37A001606
• Primes of the form k^2 + k + 9.at n=16A027758
• Numbers k such that 5*2^k + 7 is prime.at n=26A059748
• Numbers k such that floor(phi^k) is prime, where phi is the golden ratio.at n=37A059791
• Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=30A075585
• 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=9A078849
• Primes p such that the differences between the 5 consecutive primes starting with p are (2,6,6,6).at n=3A078951
• Starting positions of strings of three 8's in the decimal expansion of Pi.at n=14A083637
• In binary representation: numbers not occurring in their factorial.at n=43A093685
• Prime differences of tribonacci numbers.at n=18A113239
• Lesser of a twin-prime pair where both are expressible as the sum of two triangular numbers.at n=35A118638
• Primes congruent to 58 mod 59.at n=32A142785
• Primes congruent to 10 mod 61.at n=40A142808
• Primes p such that continued fraction of (1 + sqrt(p))/2 has period 9: primes in A143577.at n=39A146354
• Primes of the form 20n^2+8n+1.at n=13A154405
• Let m = A002445(n); then a(n) = largest member of A001359 (the lesser twin primes sequence) <= m.at n=22A156053
• Primes p such that floor(phi^p) is prime.at n=33A168033
• Primes of form a^2+b^2 such that a^4+b^4 and a^8+b^8 are primes.at n=13A182313
• Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 3*b^2.at n=17A216555
• Numbers n such that the n-th Lucas number is prime and can be written in the form a^2 + 2*b^2.at n=28A216562