617093

Appears in sequences

• Numerators of coefficients for central differences M_{4}^(2*n).at n=13A002675
• Numerators of the Taylor coefficients of (e^x-1)^2.at n=27A002678
• Sarrus numbers k such that k-1 and k+1 have the same number of prime divisors (counted with multiplicity).at n=9A086806
• a(n)=2*(4^n-1)/denominator(B(2n)) where B(k) denotes the k-th Bernoulli number.at n=14A090648
• Pseudoprimes divisible by a smaller pseudoprime.at n=29A215150
• Fermat pseudoprimes to base 2 with three prime factors divisible by a smaller Fermat pseudoprime to base 2.at n=12A215944
• Composite integers k satisfying 2^d == 2^(k/d) (mod k) for all d|k and that are not Super-Poulet (A050217).at n=9A291602
• Numbers k > 1 such that 2^k == 2 (mod k) and gcd(k, 3^k - 3) = 1.at n=14A300762
• Numbers k such that 2^(k-1) == 1 (mod k) and lpf(k)-1 does not divide k-1.at n=23A316906
• Numbers k such that 2^(k-1) == 1 (mod k) and p-1 does not divide k-1 for every prime p dividing k.at n=20A316907
• a(n) is the smallest k with n prime factors such that 2^(k-1) == 1 (mod k) and p-1 does not divide k-1 for every prime p dividing k.at n=1A316908
• Base-2 Fermat pseudoprimes k such that (k-1)/ord(2, k) > (m-1)/ord(2, m) for all base-2 Fermat pseudoprimes m < k, where ord(2, k) is the multiplicative order of 2 modulo k.at n=18A367319
• a(n) are the denominators corresponding to A370825(n).at n=27A370826