Triangle Triples (noch nicht übersetzt)
Problem 378
Let T(n) be the nth triangle number, so T(n)=n(n+1)2.
Let dT(n) be the number of divisors of T(n).
E.g.: T(7)=28 and dT(7)=6.
Let Tr(n) be the number of triples (i,j,k) such that 1≤i<j<k≤n and dT(i)>dT(j)>dT(k).
Tr(20)=14, Tr(100)=5772, and Tr(1000)=11174776.
Find Tr(60000000).
Give the last 18 digits of your answer.