172900

Appears in sequences

• Fermat coefficients.at n=32A000970
• Quadrinomial coefficients.at n=18A005720
• Unitary harmonic numbers (those for which the unitary harmonic mean is an integer).at n=28A006086
• Number of independent components for a Weyl tensor in n dimensions.at n=35A052472
• Infinitary harmonic numbers: harmonic mean of infinitary divisors is an integer.at n=22A063947
• Numbers which in at least two ways are the product of two distinct numbers with the same digits (leading zeros are forbidden).at n=5A077760
• a(n) = (-1)^(n+1) * n*(n-1)*(n-4)*(n+1)/12.at n=37A167387
• Bi-unitary harmonic numbers.at n=28A286325
• G.f. = Phi^5, where Phi = g.f. for A028930.at n=32A328530
• Tri-unitary harmonic numbers: numbers k such that the harmonic mean of the tri-unitary divisors of k is an integer.at n=23A335387
• Unitary arithmetic numbers k whose mean unitary divisor is a unitary divisor of k.at n=10A353039
• Infinitary arithmetic numbers k whose mean infinitary divisor is an infinitary divisor of k.at n=11A361387
• Bi-unitary arithmetic numbers k whose mean bi-unitary divisor is a bi-unitary divisor of k.at n=15A361787