[seqfan] Re: Like A6919, but starting with 20

[Sean A. Irvine]

All these kinds of sequences have been hammered a lot by the integer
factorization folk.  You can find plenty of results at factordb.com, e.g.:

http://factordb.com/sequences.php?se=10&aq=20&action=last20&fr=0&to=100

Tricky start points include 49, 146, 242, 312, ...


On Sat, 8 Oct 2022 at 03:19, Alonso Del Arte <alonso.delarte at gmail.com>
wrote:

>  The 13th term of A6919 is a prime number, thereby reaching a fixed point.
> I've played around with similar sequences with different starting points.
> Most of the ones I've looked at quickly reach a prime. But the one starting
> with 20, if my calculations are correct, goes like this
>
> 20, 225, 3355, 51161, 114651, 3312739, 17194867, 194122073, 709273797,
> 39713717791, 113610337981, 733914786213, 3333723311815403,
> 131723655857429041, 772688237874641409, 3318308475676071413
>
> I do believe this one too reaches a prime eventually. Can someone verify
> what I've got so far?
>
> Al
>
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