# [seqfan] Re: how is A177018 defined?

Maximilian Hasler maximilian.hasler at gmail.com
Fri Jun 18 15:31:46 CEST 2010

```The sequence is created by the following code, which I tried to make
as clear as possible:

n=0; c=0;for(i=1,99, t = n+c+A067076(c); if( t%2 == 1 && isprime(t),
print1(n", "); c++,/*else*/ n++ ))

3, 3, 3, 4, 4, 5, 5, 6, 8, 8, 10, 11, 11, 12, 14, 16, 16, 18, 19, 19,
21, 22, 24, 27, 28, 28, 29, 29, 30, 36, 37, 39, 39, 43, 43, 45, 47,
48, 50, 52, 52, 56, 56,

Maximilian

On Fri, Jun 18, 2010 at 8:50 AM, Richard Mathar
<mathar at strw.leidenuniv.nl> wrote:
>
> I have problems understanding the (apparently simple)
> http://oeis.org/classic/A177018
> "Numbers n such that n+A067076+A001477 is odd prime"
> Why are values occurring more than once?
> Which indices (or index combinations) are missing in the definition?
>
> If we use "Numbers n such that n+A067076(n)+A001477(n) is prime",
> which is of course the same as
> "Numbers n such that 2n+A067076(n) is prime"
> we get the very different
> 1,2,6,9,12,23,28,29,32,36,39,43,49,52,59,64,69,73,87,99,..
>
> Lead by the examples I considered "Smallest k such that
> k+A067076(n+1)+A001477(n) is an odd prime"
> but this doesn't match either.
>
> RJM
>
>
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>

```