I just wrote:
> a = -95 {2264832171464196191}
> a = -37 {361, 2264832171464196133}
> a = -23 {2264832171464196119}
>
> Might there be a larger region?
To partially answer my own query, I suppose what makes the above
"region" special is that 2264832171464196096 is a product of even
powers of 2, 3, (5) and 7 with the only zero-digit near the end. :)