809 B
809 B
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f4e61000cf542c50fff9 | Problem 378: Triangle Triples | 5 | 302040 | problem-378-triangle-triples |
--description--
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(60 000 000). Give the last 18 digits of your answer.
--hints--
euler378()
should return 147534623725724700.
assert.strictEqual(euler378(), 147534623725724700);
--seed--
--seed-contents--
function euler378() {
return true;
}
euler378();
--solutions--
// solution required