977 B
977 B
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f4ab1000cf542c50ffbe | Problem 319: Bounded Sequences | 5 | 301975 | problem-319-bounded-sequences |
--description--
Let x1, x2,..., xn be a sequence of length n such that:
x1 = 2
for all 1 < i ≤ n : xi-1 < xi
for all i and j with 1 ≤ i, j ≤ n : (xi) j < (xj + 1)i
There are only five such sequences of length 2, namely: {2,4}, {2,5}, {2,6}, {2,7} and {2,8}. There are 293 such sequences of length 5; three examples are given below: {2,5,11,25,55}, {2,6,14,36,88}, {2,8,22,64,181}.
Let t(n) denote the number of such sequences of length n. You are given that t(10) = 86195 and t(20) = 5227991891.
Find t(1010) and give your answer modulo 109.
--hints--
euler319()
should return 268457129.
assert.strictEqual(euler319(), 268457129);
--seed--
--seed-contents--
function euler319() {
return true;
}
euler319();
--solutions--
// solution required