117800

Appears in sequences

• Stirling numbers of the first kind: s(n+2, n).at n=30A000914
• Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=19A001599
• Numbers whose divisors' harmonic and arithmetic means are both integers.at n=16A007340
• Numbers n such that harmonic mean of the divisors of n is a prime.at n=8A074247
• Harmonic numbers (A001599) which are not perfect (A000396).at n=15A090945
• a(n) = smallest number m such that m*tau(m)/sigma(m) = n, or 0 if no such m exists.at n=18A091911
• Harmonic numbers that are not multiply-perfect.at n=11A140798
• Corresponding values of arithmetic means of divisors of numbers from A007340.at n=34A157848
• Corresponding values of arithmetic means of divisors of numbers from A007340.at n=37A157848
• a(n) = the smallest natural numbers m such that product of harmonic mean of the divisors of n and harmonic mean of the divisors of m are integers.at n=36A176802
• Ordered Stirling numbers S1(n,k) >= 0.at n=40A193245
• Number of (n+1)X(1+1) 0..3 arrays with the upper median plus the lower median minus the minimum of every 2X2 subblock equal.at n=4A237204
• Number of (n+1)X(5+1) 0..3 arrays with the upper median plus the lower median minus the minimum of every 2X2 subblock equal.at n=0A237208
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the upper median plus the lower median minus the minimum of every 2X2 subblock equal.at n=10A237211
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the upper median plus the lower median minus the minimum of every 2X2 subblock equal.at n=14A237211
• Numbers n such that A000203(2*n) divides 2*n*A045917(n).at n=25A245629
• Number of ways to select 3 disjoint point triples from an n X n X n triangular point grid, each point triple forming a 2 X 2 X 2 triangle.at n=8A289224
• Nearest integer to variance of n-th row of Pascal's triangle.at n=12A301280
• 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=11A325022
• Numbers k such that the continued fraction of the harmonic mean of the divisors of k contains a single distinct element.at n=28A349476