# [seqfan] Re: A080906?

Robert Israel israel at math.ubc.ca
Sun Dec 7 07:26:27 CET 2008

```Assuming your interpretation is right, the 4-digit entries should be

1103, 1117, 1123, 1129, 1153, 1171, 1303, 1307, 1319, 1361, 1367, 1373,
1723, 1741, 1747, 1753, 1759, 1783, 1789, 1907, 1913, 1931, 1973, 1979,
1997, 2311, 2341, 2347, 2371, 2383, 2389, 2903, 2917, 2953, 2971, 3119,
3137, 3167, 3719, 3761, 3767, 3779, 3797, 4111, 4129, 4153, 4159, 4337,
4373, 4397, 4703, 4723, 4729, 4759, 4783, 4789, 5303, 5323, 5347, 5903,
5923, 5953, 6113, 6131, 6143, 6173, 6197, 6703, 6719, 6737, 6761, 6779,
7103, 7129, 7159, 7307, 7331, 7907, 7919, 7937, 8311, 8317, 8329, 8353,
8389, 8923, 8929, 8941, 8971, 9719, 9743, 9767

and there are 3223 six-digit entries.

Cheers,
Robert Israel

On Sat, 6 Dec 2008, zak seidov wrote:

> Dear SeqFans,
>
> anyone may wish to edit this:
>
> 1. 23 is missed
> 2. terms after 1373 are wrong
> 3. add more terms
> 4. in %N, it'd be Prime numbers?
>   otherwise why 22 32 52 72 missed?
>
> thx, zak
>
> PS Were i editor i'd returm it to author(?)
>
> %I A080906
> %S A080906 37,53,73,1103,1117,1123,1129,1153,1171,1303,1307,1319,1361,1367,1373,
> %T A080906 1523,1531,1543,1553,1559,1567,1571,1579,1583,1597
> %N A080906 Numbers with 2k digits such that the first k digits and the last k digits
>               are both prime numbers.
> %F A080906 P. Giannopoulos, The brainteasers (unpublished)
> %Y A080906 Sequence in context: A092105 A101938 A060330 this_sequence A101940 A036540
>               A141166
> %Y A080906 Adjacent sequences: A080903 A080904 A080905 this_sequence A080907 A080908
>               A080909
> %K A080906 base,easy,nonn
> %O A080906 0,1
> %A A080906 P. Giannopoulos (pgiannop1(AT)yahoo.com), Mar 31 2003
>
>
>
>
>
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>

```