Let be a fixed integer greater than . The sequence , , , is defined as follows:
Find the greatest for which the sequence contains consecutive terms divisible by .
[i]
Let be a fixed integer greater than . The sequence , , , is defined as follows:
Find the greatest for which the sequence contains consecutive terms divisible by .
[i]
We need to determine the greatest such that the sequence defined by:
contains consecutive terms divisible by .
Firstly, we observe the initial terms of the sequence . These are:
Next, we analyze terms where . For such , the value of is:
The first few terms for will therefore depend linearly on the initial terms as follows:
- .
- Continuing in the same pattern, each for is a sum of prior terms.
To investigate divisibility by , consider the sequence from elements to . In particular, initial terms like etc., imply none of the are divisible by because all are powers of 2 less than and is odd.
As we proceed with computing , each term is a combination of earlier terms:
- Note that by Fermat's Little Theorem (since is an odd integer greater than 1 and is not divisible by ).
- Therefore, the sums of powers of 2, modulo , repeat patterns that emerge from the initial terms.
As for only sums up over terms bounded within a consistent modulus pattern, the maximal contiguous streak of terms divisible by can only reach a certain finite length.
Since no set of the base terms are divisible by individually, the calculation indicates a maximal streak of contiguous terms with any division pattern under .
Thus, the largest for which the sequence contains consecutive terms divisible by is: