# [seqfan] Re: I wonder

Robert G. Wilson v rgwv at rgwv.com
Sun Jul 18 07:54:43 CEST 2010

```Et al,

Again using Mathematica: Select[f at s, IntegerQ at Sqrt@# &]
{4, 16, 25, 64, 81, 196, 400, 676, 1521, 3721, 4761, 12321, 21609, 27556,
80656, 93636, 106929, 383161, 398161, 410881, 461041, 492804, 509796,
579121, 617796, 657721, 968256, 992016, 1151329, 1703025, 2140369, 2301289,
2954961, 3290596, 3602404, 4024036, 7059649, 8179600, 10876804}

Bob.
--------------------------------------------------
From: "Vladimir Shevelev" <shevelev at bgu.ac.il>
Sent: Saturday, July 17, 2010 5:00 AM
To: "Sequence Fanatics Discussion list" <seqfan at list.seqfan.eu>
Subject: [seqfan] Re: I wonder

> Many perfect squares in {a(i)}. The corresponding characteristic sequence
> for them is: {1,0,0,1,1,0,1,1,0,0,1,0,0,1 (...)}. Up to now it coincides
> with A083035. Continue a research: how many coinciding terms among the
> first n ones?  It is truth, I am not  feeling what does lead a such
> research to? But you could try.
>
> Regards,
>
> ----- Original Message -----
> From: Veikko Pohjola <veikko at nordem.fi>
> Date: Saturday, July 17, 2010 10:28
> Subject: [seqfan]  I wonder
> To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
>
>> Might these be of some more general interest?
>> 1. The sequence a(i) of the integer terms of a(n) =
>> n^2/PrimePi(n), n=2,3,4,....
>> a(i) = 4, 8, 12, 16, 25, 50, 64, 81, 90, 99, 196, 242, 384, 400, ...
>> 2. The sequence n(i) of the integer terms of a(n)
>> n(i) = 2, 4, 6, 8, 10, 20, 24, 27, 30, 33, 56, 66, 96, 100, ...
>>
>> For me, so far, they just look nicely progressing sequences.
>> Veikko
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>