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* fix: clean-up Project Euler 161-180 * fix: corrections from review Co-authored-by: Tom <20648924+moT01@users.noreply.github.com> Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>
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id, title, challengeType, forumTopicId, dashedName
| id | title | challengeType | forumTopicId | dashedName |
|---|---|---|---|---|
| 5900f4141000cf542c50ff26 | Problem 167: Investigating Ulam sequences | 5 | 301801 | problem-167-investigating-ulam-sequences |
--description--
For two positive integers a and b, the Ulam sequence U(a,b) is defined by {U{(a,b)}\_1} = a, {U{(a,b)}\_2} = b and for k > 2, {U{(a,b)}\_k} is the smallest integer greater than {U{(a,b)}\_{(k-1)}} which can be written in exactly one way as the sum of two distinct previous members of U(a,b).
For example, the sequence U(1,2) begins with
1, 2, 3 = 1 + 2, 4 = 1 + 3, 6 = 2 + 4, 8 = 2 + 6, 11 = 3 + 8
5 does not belong to it because 5 = 1 + 4 = 2 + 3 has two representations as the sum of two previous members, likewise 7 = 1 + 6 = 3 + 4.
Find \sum {U(2, 2n + 1)_k} for 2 ≤ n ≤ 10, where k = {10}^{11}.
--hints--
ulamSequences() should return 3916160068885.
assert.strictEqual(ulamSequences(), 3916160068885);
--seed--
--seed-contents--
function ulamSequences() {
return true;
}
ulamSequences();
--solutions--
// solution required