A countdown:

4, 6, 6, 0, 3, 2, 0, 1, 2, ?

How does it end? And why?

The "?" stands for a number. Which one?
And of course the interesting part is: What's the rule behind this specific countdown?

Hint 1 (about the title):

While the correct answer was already given, there is this T-yosc bit of the title. As per request, here is a hint specifically about that:

a very typical countdown

Hint 2 (if Hint 1 is not enough):

...that tells you how far I turned the real hint

Hint 3 (if Hint 2 is not enough):

...or rotated

  • $\begingroup$ Since you are too fast for me in solving riddles, I just post my own. I hope you like this one, I tried to verify that it has not been asked before. If necessary, hints will follow. $\endgroup$ Jan 19, 2018 at 15:25
  • $\begingroup$ Now you are also too fast for me in solving my riddles. - I need to learn. $\endgroup$ Jan 19, 2018 at 15:50

1 Answer 1


It ends in

0: this is the reverse of OEIS sequence A091967, which gives the $n$th member of OEIS sequence $\mathrm{A}n$.

  • $\begingroup$ That's just... devious! $\endgroup$
    – Phylyp
    Jan 19, 2018 at 15:44
  • 1
    $\begingroup$ @Phylyp: Yes, it does. It's a bit far fetched, but might have become clearer with hints. However, Deusovi was way too fast for any hints to be posted. In an attempt not to spoil, I'll post the relevance of T-yosc as a separate answer. In case you might want to figure out that bit for yourself, I'll wait a bit. Or just tell me to cough it up already. $\endgroup$ Jan 21, 2018 at 3:25
  • 2
    $\begingroup$ About the title, yosc is actually oeis (the name of the encyclopedia about integer sequences) rotated by 10 $\endgroup$ Jan 23, 2018 at 10:53
  • 2
    $\begingroup$ So basically its a "ROTten" title? :-) $\endgroup$
    – Phylyp
    Jan 23, 2018 at 11:57
  • 1
    $\begingroup$ Nothing happened for a while, so I think it's about time to clarify the latest bit. And with basically everything already said, I hope you don't mind me just putting it in a comment. - The riddle sequence is a countdown, and, as Deusovi solved within seconds, it literally is a oeis countdown. The most archetypical term for a countdown I can think of is "T-10". ROT10 of oeis is yosc, as Florian pointed out. Combine this to T-yosc. So you are right, Phylyp, it's a ROTten title that tried to give a hint but not to reveal too much. $\endgroup$ Apr 24, 2018 at 20:51

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