6480000

Appears in sequences

• Denominator of Sum_{k=1..n} phi(k)/k^4.at n=4A072161
• Denominator of Sum_{k=1..n} phi(k)/k^4.at n=5A072161
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k even entries that are followed by a smaller entry (n>=0, k>=0).at n=37A134434
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k odd entries that are followed by a smaller entry (n >= 0, k >= 0).at n=35A134435
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k adjacent pairs of the form (odd,even) (0<=k<=floor(n/2)).at n=40A145891
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k runs of odd entries (1<=k<=ceiling(n/2)). For example, the permutation 321756498 has 3 runs of odd entries: 3, 175 and 9.at n=31A152666
• a(n) = n^4*(n+1)^2/2.at n=15A163274
• Denominators of poly-Cauchy numbers c_n^(4).at n=4A224098
• Denominators of poly-Cauchy numbers of the second kind hat c_n^(4).at n=4A224105
• a(n) = [n/2]!*[(n+1)/2]!*C([n/2],4)*C([(n+1)/2],4).at n=10A226285
• Number of solutions to gcd(x^2 + y^2 + z^2 + t^2 + h^2, n) = 1 with x,y,z,t,h in [0,n-1].at n=29A238533
• Number of (2+1)X(n+1) arrays of permutations of 0..n*3+2 with each element having index change +-(.,.) 0,0 0,2 or 2,1.at n=8A264196
• a(n) = phi(n^5 - 1)/5 where phi is A000010.at n=30A319214
• a(n) = Product_{d|n} (A253139(n) / tau(d)) where A253139(n) = lcm_{d|n} tau(d).at n=15A334470
• Powerful superabundant numbers: numbers m such that psigma(m)/m > psigma(k)/k for all k < m, where psigma(k) is the sum of powerful divisors of k (A183097).at n=28A349111
• a(n) = n^4*tau(n).at n=29A386013