1.0 KiB
1.0 KiB
id | title | challengeType | forumTopicId |
---|---|---|---|
5900f4831000cf542c50ff95 | Problem 278: Linear Combinations of Semiprimes | 5 | 301928 |
--description--
Given the values of integers 1 < a1 < a2 <... < an, consider the linear combination q1a1 + q2a2 + ... + qnan = b, using only integer values qk ≥ 0.
Note that for a given set of ak, it may be that not all values of b are possible. For instance, if a1 = 5 and a2 = 7, there are no q1 ≥ 0 and q2 ≥ 0 such that b could be 1, 2, 3, 4, 6, 8, 9, 11, 13, 16, 18 or 23.
In fact, 23 is the largest impossible value of b for a1 = 5 and a2 = 7. We therefore call f(5, 7) = 23. Similarly, it can be shown that f(6, 10, 15)=29 and f(14, 22, 77) = 195.
Find ∑ f(pq,pr,q*r), where p, q and r are prime numbers and p < q < r < 5000.
--hints--
euler278()
should return 1228215747273908500.
assert.strictEqual(euler278(), 1228215747273908500);
--seed--
--seed-contents--
function euler278() {
return true;
}
euler278();
--solutions--
// solution required