425040

Appears in sequences

• Numbers that can be expressed as the difference of the squares of primes in exactly seventeen distinct ways.at n=6A092013
• a(n) = denominator(Sum_{k=1..n} 1/(prime(k)-1)).at n=14A128646
• a(n) = denominator(Sum_{k=1..n} (-1)^(k+1)/(prime(k)-1)).at n=14A128648
• Numbers with prime factorization pqrstu^4.at n=5A190388
• Numbers k such that Euler phi(Dedekind psi(k)) > k.at n=30A196200
• a(n) = 10*binomial(n+4, 5).at n=20A266732
• Numbers n such that the multiplicative group modulo n is the direct product of 7 cyclic groups.at n=29A272597
• Denominators of r(n) := Sum_{k=0..n-1} 1/Product_{j=0..4} (k + j + 1), for n >= 0, with r(0) = 0.at n=19A300299
• Primitive 4-abundant numbers: Numbers k such that sigma(k) > 4k (A068404) all of whose proper divisors d are 4-deficient numbers (having sigma(d) < 4d).at n=31A307114
• a(n) = denominator of Sum_{1 <= i < j <= d(n)} 1/(d_j - d_i), sum over ordered pairs of divisors of n, where d(n) is the number of divisors of n.at n=23A330078
• a(n) = n! * Sum_{k=0..floor(n/2)} k^(n - 2*k)/k!.at n=8A345747
• Primitive terms of A023198: numbers k with the property sigma(k)/k >= 4 that are not divisible by any other number with that property.at n=33A392936