# [seqfan] Re: Is this sequence interesting?

Andrew Weimholt andrew.weimholt at gmail.com
Fri Dec 18 08:02:31 CET 2009

```On 12/17/09, Andrew Weimholt <andrew.weimholt at gmail.com> wrote:
> On Thu, Dec 17, 2009 at 9:25 PM, Andrew Weimholt
>  <andrew.weimholt at gmail.com> wrote:
>  > Smallest unused number such that for any prime p, (p+1)|a(n) implies p|a(n+1)
>
>

Maximillian Hasler caught another error and sent me
the following corrected sequence in an off-list message.
Thanks Max! :-)

1, 2, 3, 4, 6, 10, 5, 7, 8, 21, 12, 330, 31610, 9, 14, 13, 11, 15, 16,
42, 5330, 409, 17, 18, 170, 19, 20, 57, 22, 23, 24, 53130,
993933017762600187592585366884582410,  [very large number], ...

Note that the [very large number] will not be divisible by 2 or 3, so
there will be no divisors of the form p+1 for prime p. So the term
following the [very large number] will be 25 and the sequence continues
from there as before...

1, 2, 3, 4, 6, 10, 5, 7, 8, 21, 12, 330, 31610, 9, 14, 13, 11, 15, 16,
42, 5330, 409, 17, 18, 170, 19, 20, 57, 22, 23, 24, 53130,
993933017762600187592585366884582410,  [very large number], 25,
27, 28, 39, 30, 290, 29, 31, 32, 651, 34, 33, 36, 5610, 606139356770,
4471670685645331592970549159770045950729, 35, 37, 38, 74, 73, 40, 399,
44, 129, 41, 43, 45, 46, 47, 48, 2497110,
18357856193046830514707003334732167656898967581695292011731472733408286953690,
[ another very large number ], 49, ...

Andrew

```