15790321

Properties

Appears in sequences

• Largest prime factor of 2^n + 1.at n=28A002587
• Largest prime factor of 16^n + 1.at n=7A002590
• Triangle of (Gaussian) q-binomial coefficients for q=-16.at n=29A015139
• a(n) = n^6 - n^5 + n^4 - n^3 + n^2 - n + 1.at n=16A060888
• Zsigmondy numbers for a = 4, b = 1: Zs(n, 4, 1) is the greatest divisor of 4^n - 1^n (A024036) that is relatively prime to 4^m - 1^m for all positive integers m < n.at n=27A064080
• a(n) = (lcm_{k=0..n} (2^k + 1))/(lcm_{k=0..n-1} (2^k + 1)).at n=27A066845
• Triangular array read by rows: row s contains integers of the form (2^s+1)/(2^r+1) in order of increasing r <= s-1.at n=31A079665
• Let Cn(x) be the n-th cyclotomic polynomial; a(n) is the first prime Cn(x) after Cn(1).at n=27A085399
• A006530(x)=2 is a local minimum if x=2^n. Running upward with argument x, the largest prime divisor should increase. The value of first peak is a(n).at n=27A102643
• A006530(x)=2 is a local minimum if x=2^n. Running upward with argument x, the largest prime divisor should increase. The value of first peak is a(n).at n=28A102643
• a(n) is the least prime such that the multiplicative order of 4 mod a(n) equals n.at n=27A112092
• List of primitive prime divisors of the numbers (4^n-1)/3 (A002450) in their order of occurrence.at n=49A129735
• Primes which divide none of overpseudoprimes to base 2 (A141232).at n=32A144755
• Aurifeuillian primes of the form 2^k+1.at n=17A153443
• Primes in A153601.at n=27A153602
• A list of primes written in order of their first appearance in a table of prime factorizations of 2^k+1, k=1,2,... .at n=33A158895
• The unique primitive prime factor of 2^n-1 for the n in A161508.at n=33A161509
• Numbers k (between 2^(m-1) and 2^m) such that 2^(k-1) == 1 (mod k) and 2^(k-1-m) == k - 2^p (mod k) for some p > 0 with 2^p < k.at n=34A167612
• a(n+1) = 2*a(n) + A014017(n+5), a(0) = 0.at n=28A191497
• Primes of the form Phi(phi(k),2), the phi(k)-th cyclotomic polynomial evaluated at 2, where phi is the Euler totient function.at n=13A211876