237510

Appears in sequences

• Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=22A001599
• Numbers whose divisors' harmonic and arithmetic means are both integers.at n=19A007340
• Coordination sequence for 4-dimensional I-centered cubic orthogonal lattice.at n=39A008532
• (1+e)-harmonic numbers: harmonic mean of (1+e)-divisors is an integer.at n=22A053783
• Triangle read by rows: T(n,k) = binomial(3n+3, k)*(n-k+1)/(n+1).at n=51A064282
• Numbers n such that harmonic mean of the divisors of n is a prime.at n=9A074247
• Product of all primes contained as binary substrings in binary representation of n.at n=29A078828
• Harmonic numbers (A001599) which are not perfect (A000396).at n=18A090945
• a(n) = smallest number m such that m*tau(m)/sigma(m) = n, or 0 if no such m exists.at n=28A091911
• Sixth column of (1,5)-Pascal triangle A096940.at n=25A096943
• Harmonic numbers that are not multiply-perfect.at n=14A140798
• a(n) = lcm(n,n+1,n+2,n+3,n+4,n+5)/60.at n=24A189046
• Coefficients of (x^(1/5)*d/dx)^n for positive integer n.at n=29A223535
• Number of ways 2*n-1 people can vote on three candidates so that the Condorcet paradox arises.at n=25A277935
• Harmonic numbers m from A001599 such that m*(m-tau(m))/sigma(m) is not an integer, where k-tau(k) = the number of nondivisors of k (A049820), tau(k) = the number of divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).at n=14A325022
• Harmonic numbers (A001599) with a record harmonic mean of divisors.at n=12A335316
• Harmonic numbers k such that k*p is not a harmonic number for all the primes p that do not divide k.at n=9A335369
• Numbers k such that the continued fraction of the harmonic mean of the divisors of k contains a single distinct element.at n=31A349476
• G.f. A(x) satisfies A(x) = 1 + x + x^4*A(x)^3.at n=26A366556
• Integers x such that there exist two integers 0<x<=y<=z such that psi(x) = psi(y) = psi(z) = x + y + z.at n=5A385852