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        riddles >> general problem-solving / chatting / whatever >> Autobiographical / curious numbers
        
(Message started by: BenVitale on Oct 7^th, 2009, 10:05am)

Title: Autobiographical / curious numbers
Post by BenVitale on Oct 7^th, 2009, 10:05am

I came across Autobiographical Numbers on Tanya Khovanova’s Math Blog (http://blog.tanyakhovanova.com/?p=8)

and on arxiv file (http://arxiv.org/PS_cache/arxiv/pdf/0803/0803.0270v1.pdf)

The formal definition is : an autobiographical number is a number N such that the first digit of N counts how many zeroes are in N, the second digit counts how many ones are in N and so on. In our example, 1210 has 1 zero, 2 ones, 1 two and 0 threes.

the autobiographies can not have more than 10 digits

1210 is the smallest autobiographical number.

Tanya Khovanova wrote:

Quote:

... I would vote against the name curious, and time will show us which name sticks better to this sequence.

Why does she say that?

The On-Line Encyclopedia of Integer Sequences doesn't seem to make a distinction between curious and autobiographical numbers

http://www.research.att.com/~njas/sequences/?q=curious+numbers&sort=0&fmt=0&language=english&go=Search

Title: Re: Autobiographical / curious numbers
Post by nega1sqrt on Nov 5^th, 2009, 6:50pm

http://en.wikipedia.org/wiki/Self-descriptive_number
This has some information about autobiographical numbers.