# [seqfan] Re: Numbers impossible to produce

Eric Angelini Eric.Angelini at kntv.be
Thu Apr 14 16:18:04 CEST 2011

```Many thanks to Claudio and Peter who
Best,
E.

Envoyé d'un iPhone

Le 14 avr. 2011 à 15:14, "Peter Pein" <petsie at dordos.net> a écrit :

> Am 14.04.2011 13:41, schrieb Eric Angelini:
>> Hello SeqFans,
>>
>> The integer 126 produces 38 like this:
>>
>>  1 2 6
>>   3 8
>>
>> A digit on the base line is the addition
>> of the two closest digits above it.
>>
>> What does the integer 176 produce?
>> We decide that if the sum a+b of the said
>> digits is greater than 9, than we subtract
>> a from b (or b from a if a>  b):
>>
>>  1 7 6
>>   8 1
>>
>> So, we managed to produce 38 and 81; but
>> what could be the smallest number that
>> would be impossible to produce, according
>> to the above rule?
>>
>> Best,
>> É.
>>
>>
>>
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>
> here are the least three-digit numbers which produce 0,1,...,99:
>
> {555, 556, 557, 558, 559, 550, 551, 552, 553, 554, 100, 101, 102, \
> 103, 104, 105, 106, 107, 108, 109, 200, 110, 111, 112, 113, 114, 115, \
> 116, 117, 118, 300, 210, 120, 121, 122, 123, 124, 125, 126, 127, 377, \
> 310, 220, 130, 131, 132, 133, 134, 135, 136, 388, 387, 146, 147, 140, \
> 141, 142, 143, 144, 145, 155, 156, 157, 158, 159, 150, 151, 152, 153, \
> 154, 166, 165, 164, 169, 259, 250, 160, 161, 162, 163, 177, 176, 175, \
> 174, 173, 194, 193, 170, 171, 172, 188, 187, 186, 185, 184, 183, 182, \
> 270, 180, 181}
>
> Cheers,
> Peter
>
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>
```