[seqfan] Re: https://oeis.org/A254211 Finite?

[Heinz, Alois]

It is a nice problem.

My conjecture is: The sequence is infinite.

I have computed the first 1000 terms and the sequence
does not seem to end early.

Best regards, Alois

Am 27.01.2015 um 12:26 schrieb Ron Hardin:
> Right, the every partial sum from either end is never prime.  (iv) could as well start k=1 and just duplicate (iii) once.
>
>   
> rhhardin at mindspring.com
> rhhardin at att.net (either)
>
>
>> ________________________________
>> From: Neil Sloane <njasloane at gmail.com>
>> To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
>> Sent: Monday, January 26, 2015 10:18 PM
>> Subject: [seqfan] Re: https://oeis.org/A254211 Finite?
>>
>>
>> Just to clarify the definition:
>> These are vectors [u_1 ... u_n] such that
>> (i)   u_i = 1,2 or 3
>> (ii)  u_i != u_{i+1}
>> (iii) Sum_{i=1..k} u_i != prime for k=1..n
>> (iv) Sum_{i=k..n} u_i != prime for k=2..n
>> - is that right?
>>
>> Best regards
>> Neil