## Problem 656

A place to air possible concerns or difficulties in understanding ProjectEuler problems. This forum is not meant to publish solutions. This forum is NOT meant to discuss solution methods or giving hints how a problem can be solved.
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vamsikal3
Posts: 113
Joined: Sat Oct 01, 2016 9:25 am

### Problem 656

Can someone verify that the 21st value of n which gives a palindromic sub-sequence for alpha = square_root(31) is <removed by moderator>? The value is too large, otherwise I would have tried to brute-force it somehow.

EDIT: I was actually able to brute-force the 21st value of n for which we have a palindromic prefix for alpha = square_root(31). Also, I was able to solve the problem with a minor hint from Cot-O-Bus over PM.
Last edited by vamsikal3 on Sun Feb 24, 2019 9:28 am, edited 1 time in total.
my friend key --> 990813_OZPwQtCjkD6KlvxirOoTSZxccMFsuw1L

Cot-O-Bus
Posts: 6
Joined: Thu Sep 27, 2018 10:18 am

### Re: Problem 656

.
Last edited by Cot-O-Bus on Tue Feb 19, 2019 5:02 pm, edited 1 time in total.

Animus
Posts: 1907
Joined: Sat Aug 16, 2014 1:23 pm

### Re: Problem 656

This forum is meant for clarifying questions concerning the problem statements. Please adhere the forum rules shown above, especially these:
In particular don't post any code fragments or results.

Don't start begging others to give partial answers to problems

Don't ask for hints how to solve a problem.

Many participants take pride in their achievements. Therefore it is not appropiate to ask for help for recent problems that have not even reached 100 solvers.

This problem has not even been out for 2 days yet!

vamsikal3
Posts: 113
Joined: Sat Oct 01, 2016 9:25 am

### Re: Problem 656

Instead of posting the partial result on the forum, I probably should have asked someone to verify via PM.

Can I PM someone to verify my result for the 21st term in the sequence given in the example for square_root(31)?

Thanks,
Vamsi
my friend key --> 990813_OZPwQtCjkD6KlvxirOoTSZxccMFsuw1L

RobertStanforth
Posts: 1339
Joined: Mon Dec 30, 2013 11:25 pm

### Re: Problem 656

vamsikal3 wrote:
Tue Feb 19, 2019 4:17 am
Can I PM someone to verify my result for the 21st term in the sequence given in the example for square_root(31)?
No, that is still not the purpose of this forum.
As Animus said, "it is not appropiate to ask for help for recent problems that have not even reached 100 solvers".

vamsikal3
Posts: 113
Joined: Sat Oct 01, 2016 9:25 am

### Re: Problem 656

Fine then, I will wait until 100 solvers have solved the problem.

We had a thread on collaborative problem solving a while ago, I do not recall the thread to place a link here. If the admins/moderators are against solvers collaborating on this forum, maybe you need to add another section where people can collaborate via PM. We are not asking for hints or algorithms or even the final answer, we just need someone to verify a partial result or two.
my friend key --> 990813_OZPwQtCjkD6KlvxirOoTSZxccMFsuw1L

Animus
Posts: 1907
Joined: Sat Aug 16, 2014 1:23 pm

### Re: Problem 656

Vamsi, we are not per se opposed to people building a small, closed group working on solving problems collaboratively.
However, this forum is in no way a closed group and should not be, so we don't want you to use this forum to do so.

Cot-O-Bus
Posts: 6
Joined: Thu Sep 27, 2018 10:18 am

### Re: Problem 656

I have had an errors at { 677, 730, 785, 842, 901, 962 }
Fixed.
Solved.

Thanks for collaboration.

jaap
Posts: 551
Joined: Tue Mar 25, 2008 3:57 pm
Contact:

### Re: Problem 656

In the wording of the problem, I don't think it is a good idea to use the letter n for two different variables - first as the index of the sequence, then as an element of T. I think it would be better to change the second use to a variable named t for example.

hk
I made it: Calculate the sum of $H_{100}(\sqrt \beta)$ for $\beta \in T$.