[seqfan] Another chemistry related sequence?

[Antti Karttunen]

Here is an idea for atomic elements related sequence that should
be reasonably well defined:

a(n) = The number of stable isotopes the element number n has.

If the information in Wikipedia is correct, the sequence should start as:
2,2,2,1,2,2,2,3,1,3,...

Note that both a(83) ( http://en.wikipedia.org/wiki/Bismuth )
and a(92) ( http://en.wikipedia.org/wiki/Uranium ) should be 0.



(Or is it? Okay, we can speculate about the eventual decaying of protons,
but... Also, I mean stable at "the normal room temperature conditions", not
inside
a particle accelerator.)


Cheers,

Antti.