# [seqfan] Re: Checking A174216

Alois Heinz heinz at hs-heilbronn.de
Mon Nov 1 20:51:48 CET 2010

```I get:

15, 27, 63, 123, 279, 567, 1143, 2307, 4623, 9447, 18927, 38283, 77139,
154839, 309747, 620463, 1241823, 2483847, 4967739, 9935607

Alois

Am 01.11.2010 07:58, schrieb Vladimir Shevelev:
> Thanks to Richard and Max for checking a(11) of A174216. Since the calculation of different terms are almost independent (except of the condition a(n)>a(n-1)), then one cannot exclude that further terms of A174216 could be true. I kindly ask you to make an independent checking of some further terms.
>
> Best regards,
>
> ----- Original Message -----
> From: Max Alekseyev<maxale at gmail.com>
> Date: Saturday, October 30, 2010 5:37
> Subject: [seqfan] Re: Checking A174216
> To: Sequence Fanatics Discussion list<seqfan at list.seqfan.eu>
> Cc: seqfan at seqfan.eu
>
>> I confirm that a(11)=18927.
>>
>> Here is my PARI/GP code for A174216, starting with the second
>> term and
>> listing all terms below 10^5:
>>
>> { a=14; for(n=10, 10^5, if( gcd(a,n-1-(-1)^n)==1, a+=1, a=2*n-
>> 4); if(
>> 2*a==3*(n-1), print1(n,", ") )) }
>>
>> 27, 63, 123, 279, 567, 1143, 2307, 4623, 9447, 18927, 38283, 77139,
>>
>> Regards,
>> Max
>>
>> On Fri, Oct 29, 2010 at 4:04 PM, Richard Mathar
>> <mathar at strw.leidenuniv.nl>  wrote:
>>> In March, I changed A174216(11) to 18927, which was reverted
>>> by the author of the sequence to 19263. Can someone independently
>>> check the terms in A174216?
>>> This concerns primarily n=11, k=18927 with A174214(k)=232257 and
>>> 3*(k-1)=464514 (all values according to my calculation).
>>>
>>> http://oeis.org/classic/?q=id%3AA174214|id%3AA174216

```