# Interesting number sequence puzzle

What's the next (last) number in the following sequence?

$1,2,3,4,5,6,8,9,10,\underline{~~?~~}$

(both mathematical and non-mathematical answers are welcome)

• oeis.org/search?q=1%2c2%2c3%2c4%2c5%2c6%2c8%2c9%2c10
– f''
Jul 3, 2016 at 19:17
• It looks to me as if OEIS doesn't contain any sequence beginning that way for which the next number is also the last (which I think is what the "(last)" is intended to mean). Jul 3, 2016 at 23:43
• The statement originally said What's the next number in the following sequence? (which is also the last one) and the sequence read 1,2,3,4,5,6,8,9,10,.... I hope my edit was correct. Jul 3, 2016 at 23:46
– TTT
Jul 4, 2016 at 16:31
• I'm sorry for my question being not too interesting in English. I'm Hungarian, so the original question was in Hungarian too. (1, 4, 5, 6, 7, 8, 10, 20, and the answer is 100) Jul 5, 2016 at 8:50

I'd plump for

$12$

Because

It is the sequence of all positive integers, $\Bbb{N^*}$, that have $1$ syllable in English.

Obviously 11

It is just normal counting

Seven ate nine,so this time nine ate seven so seven isn't there.