2018-09-30 22:01:58 +00:00
|
|
|
---
|
|
|
|
id: 5900f44e1000cf542c50ff60
|
|
|
|
title: 'Problem 225: Tribonacci non-divisors'
|
2020-11-27 18:02:05 +00:00
|
|
|
challengeType: 5
|
2019-08-05 16:17:33 +00:00
|
|
|
forumTopicId: 301868
|
2021-01-13 02:31:00 +00:00
|
|
|
dashedName: problem-225-tribonacci-non-divisors
|
2018-09-30 22:01:58 +00:00
|
|
|
---
|
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
# --description--
|
|
|
|
|
2018-09-30 22:01:58 +00:00
|
|
|
The sequence 1, 1, 1, 3, 5, 9, 17, 31, 57, 105, 193, 355, 653, 1201 ...
|
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
is defined by T1 = T2 = T3 = 1 and Tn = Tn-1 + Tn-2 + Tn-3.
|
2018-09-30 22:01:58 +00:00
|
|
|
|
|
|
|
It can be shown that 27 does not divide any terms of this sequence.In fact, 27 is the first odd number with this property.
|
|
|
|
|
|
|
|
Find the 124th odd number that does not divide any terms of the above sequence.
|
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
# --hints--
|
2018-09-30 22:01:58 +00:00
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
`euler225()` should return 2009.
|
2018-09-30 22:01:58 +00:00
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
```js
|
|
|
|
assert.strictEqual(euler225(), 2009);
|
2018-09-30 22:01:58 +00:00
|
|
|
```
|
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
# --seed--
|
2018-09-30 22:01:58 +00:00
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
## --seed-contents--
|
2018-09-30 22:01:58 +00:00
|
|
|
|
|
|
|
```js
|
|
|
|
function euler225() {
|
2020-09-15 16:57:40 +00:00
|
|
|
|
2018-09-30 22:01:58 +00:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
euler225();
|
|
|
|
```
|
|
|
|
|
2020-11-27 18:02:05 +00:00
|
|
|
# --solutions--
|
2018-09-30 22:01:58 +00:00
|
|
|
|
|
|
|
```js
|
|
|
|
// solution required
|
|
|
|
```
|