sequences Bigint NaN conversion error hangs factorfence

[katestange]

To reproduce, open this URL:
http://localhost:5173/?name=Formula&viz=FactorFence&highlight=17&seq=Formula&formula=2
Then click into the formula box and backspace the 2. The following error message pops up:

Error Message:
RangeError: NaN can't be converted to BigInt because it isn't an integer

The factorfence goes blank. The really unfortunate aspect of this is that putting the 2 back doesn't fix things... it appears you cannot recover factorfence in any way except a hard browser reload or choosing another visualizer. Tested in Firefox & Chromium.

[gwhitney]

Which milestone? Alpha or beta? I agree we should fix this.

[katestange]

I'm ok with either.