332640

Appears in sequences

• a(n) = (2*n+1)! / n!.at n=5A000407
• Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=24A001599
• a(n) = n!/5!.at n=6A001725
• Highly composite numbers: numbers n where d(n), the number of divisors of n (A000005), increases to a record.at n=33A002182
• Superabundant [or super-abundant] numbers: n such that sigma(n)/n > sigma(m)/m for all m < n, sigma(n) being A000203(n), the sum of the divisors of n.at n=27A004394
• Where records occur in A038548.at n=30A004778
• a(n) = (3*n+4)*(n+3)!/24.at n=6A005460
• Unitary harmonic numbers (those for which the unitary harmonic mean is an integer).at n=33A006086
• Numbers whose divisors' harmonic and arithmetic means are both integers.at n=21A007340
• Numbers k such that phi(k) divides sigma(k) and sigma(k)/k > sigma(m)/m for all m < k.at n=5A007668
• Theta series of A_9 lattice.at n=10A008449
• Expansion of e.g.f. arctan(log(x+1) - arcsinh(x)).at n=10A013273
• a(1)=1; for n > 1, a(n) is the smallest number with the same number of divisors as 2*a(n-1).at n=21A019505
• a(n) = (n/(n+1)) * lcm(1,2,...,n+1).at n=11A025558
• Triangular array a(n,k) = (1/k)*Sum_{i=0..k} (-1)^(k-i)*binomial(k,i)*i^n; n >= 1, 1 <= k <= n, read by rows.at n=42A028246
• Base 9 digital convolution sequence.at n=12A033646
• Triangle of numbers where k-th row contains (ij)!/(i!j!) with i+j = k+1, 1 <= i <= k.at n=22A046792
• Triangle of numbers where k-th row contains (ij)!/(i!j!) with i+j = k+1, 1 <= i <= k.at n=26A046792
• Distinct elements of A045948.at n=11A048148
• A triangle of numbers related to triangle A030527.at n=21A049374