[seqfan] Re: Sequence contains only three elements 2, 4 and 6

[Olivier Gerard]

On Sun, Mar 30, 2014 at 11:36 AM, Tw Mike <mt.kongtong at gmail.com> wrote:

> Dear Olivier,
>
> 2, 4, 6 for this:
> pn the n-th prime, p(pn) = sum(p1, p2, p3, ..., pn)
>
> Yours mike
>

I am not sure I understand what you mean. You should try to express
yourself more precisely.

The sequence for the sum of the n first prime numbers is

A007504      0, 2, 5, 10, 17, 28, 41, 58, 77, 100, 129, ...

The primes in this list are

A013918  2, 5, 17, 41, 197, 281, 7699, 8893, 22039, 24133, 25237, 28697, ...

Their index in A007504 is

A013916  1, 2, 4, 6, 12, 14, 60, 64, 96, 100, ...
The prime index of the primes in A007504 are

A020641    1, 3, 7, 13, 45, 60, 977, 1108, 2470, 2687, ...

I presume this is A13916 you were searching for.


If this is true, next time, don't be lazy, just compute more terms.
3 terms for a sequence which looks like the even numbers is not enough.

1,2,4,6,12 prime in the OEIS just gives 26 results, this is easy to browse.



Olivier