if number is 1-2, 4 or 6-8 or 12-28, 30, 32...

[Tim Peters]

[John Machin]
> === bot bait ================================
> bignum, long, fast, speed, optimize snot out of

[Emile van Sebille]
> Hook many bots this way?  ;-))

John might have, except for his later

> Is the function elegant enough?

Take it from me:  "elegant" has a weight of about minus gazillibob in a
bot's attraction algorithm.

not-as-bad-by-far-as-"practical"-but-a-loser-all-the-same-ly y'rs  - tim