prime twin pairs yielding others

[Neil Fernandez]

In message <000501c1df5e$f4394b80$e8d53841 at oemcomputer>, Rick Shepherd
<R.Shepherd at prodigy.net> writes

[...]

>18894, 211049
>21933, 248639
>22332, 253679
>34638, 410339
>
>i.e., prime(18894)=211049 is the least example of the smaller of a twin
>prime pair yielding a twin prime pair yielding a third twin prime pair in
>this manner.  All three of the smaller twins in this chain are = 29 (mod
>30).
>(Note that the third pair doesn't yield a fourth.).  I haven't yet examined
>the full chains of the three larger examples.

Hi Rick,

I've now looked at all of the numbers that you and Don listed. The only
one that belongs to a pair yielding a chain of length >3 is 253679. The
chain for that pair is of length 4.

So the sequence in which a(n) is the smaller of the first twin pair to
yield a twin pair chain of length n begins:

3, 5, 211049, 253679

Neil
-- 
Neil Fernandez