3175200

Appears in sequences

• Numbers k such that sigma(k) - usigma(k) > 3k.at n=17A063875
• Even refactorable numbers k such that the number r of odd divisors and the number s of even divisors are both odd divisors of k and k is the first number for which the triple (r,s,t) occurs, where t is the number of divisors of k.at n=22A120358
• Smallest number m having exactly n divisors d with sqrt(m/2) <= d < sqrt(2*m).at n=25A128605
• Irregular triangle T(n,k) = A096162(n,k) * A036040(n,k) * A048996(n,k) * A098546(n,k) * A178886(n,k), read by rows, 1 <= k <= A000041(n).at n=35A179236
• Irregular triangle T(n,k) = binomial(n-1,m-1)*m!*A036040(n,k), where m=A036043(n,k), read by rows, 1 <= k <= A000041(n).at n=63A181417
• Ordered forests of k increasing unordered trees on the vertex set {1,2,...,n} in which all outdegrees are <= 2.at n=41A185421
• Augmentation of the triangle A004736. See Comments.at n=38A193561
• Triangle read by rows: T(n,k) (n>=1, 1 <= k <= n) = number of permutations of [1..n] in which none of the cycle lengths are divisible by k.at n=52A213280
• Number of integers k^6 that divide 1!*2!*3!*...*n!.at n=24A248824
• Triangle read by rows, T(n,k) = (k+1)*(n+1)!*(n+k)!/((k+1)!^2*(n-k)!) with n >= 0 and 0 <= k <= n.at n=25A253284
• Sum of cubes of the first n even numbers (A016743).at n=35A254371
• a(n) = 2*n^2*binomial(2*n,n)^2, a closed form for a double binomial sum involving absolute values.at n=5A254408
• Numbers k such that uphi(k)/phi(k) > uphi(m)/phi(m) for all m < k, where phi(k) is the Euler totient function (A000010) and uphi(k) is the unitary totient function (A047994).at n=29A283052
• Numbers n such that sigma(n)/usigma(n) > sigma(m)/usigma(m) for all m < n, where sigma(n) is the sum of divisors of n (A000203) and usigma(n) is the sum of unitary divisors of n (A034448).at n=34A285906
• Denominator of Sum_{k=1..n-1} 1/(k*(n-k))^2.at n=9A304582
• Nonunitary superabundant numbers: numbers m such that nusigma(m)/m > nusigma(k)/k for all k < m, where nusigma(m) is the sum of nonunitary divisors of m (A048146).at n=32A329882
• a(n) is the smallest number m such that gcd(m, tau(m), sigma(m), pod(m)) = n where tau(k) is the number of divisors of k (A000005), sigma(k) is the sum of divisors of k (A000203) and pod(k) is the product of divisors of k (A007955).at n=26A337324
• Powerful numbers that have more divisors than any smaller powerful number.at n=35A377138
• a(n) = (3*n+1)!*(3*n)!/((2*n)!*((n+1)!)^2).at n=3A383874