1130500

Appears in sequences

• Number of permutations of 4 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/5)] (5-way heap).at n=3A178025
• Number x such that sigma(x) = usigma(x) + (-1)sigma(x), where sigma(x) is the sum of divisors of x (A000203), usigma(x) is the sum of unitary divisors of x (A034448) and (-1)sigma(x) is defined in A049060.at n=17A258106