30781

Properties

Appears in sequences

• Value of D for incrementally largest values of minimal x satisfying Pell equation x^2-Dy^2=1.at n=42A033316
• First member of a prime quadruple in a 2p-1 progression.at n=16A057327
• Prime(n) and prime(n+3) use the same digits.at n=35A069795
• Number of truncated ST-pairs O(q^n).at n=25A094866
• Primes from merging of 5 successive digits in decimal expansion of Pi.at n=8A104825
• Irregular table with first row containing the single term 3; in the n-th row, n>=2, we list in increasing order those d=2^(n+1)-a, for each term a in all the preceding rows, such that d is prime.at n=38A152871
• Expansion of (1 - 3*x - x^2)/(1 - 4*x + 2*x^3 + x^4).at n=9A195350
• Number of (w,x,y,z) with all terms in {1,...,n} and |x-y|=n-w+|y-z|.at n=39A212684
• Numbers n such that n!3 - 3 is prime, where n!3 = n!!! is a triple factorial number (A007661).at n=33A242994
• Primes p such that A001175(p) = (p-1)/6.at n=37A308791
• a(0) = 1 and a(n) = A309807(n) - A309807(n-1) for n > 0.at n=19A332955
• Primorial base emirps: prime numbers whose primorial base reversal is a different prime.at n=37A333425
• Prime numbersat n=3319