[seqfan] a(n-1)+a(n) = palindrome
Alexander P-sky
apovolot at gmail.com
Tue Oct 19 17:22:34 CEST 2010
Douglas McNeil wrote:
>A 1-indexed sequence starting at 1 seems natural enough.
>It'd seem far more artificial to me to start at 5.
> What's your argument ?
I would not consider 3, 5, 7, 9 to be palindromes !
On 10/19/10, Eric Angelini <Eric.Angelini at kntv.be> wrote:
> Hello Alexander,
> I'm forced to start with 1
> because 3 is a palindrome,
> according to the OEIS.
> So a(1) is 1 and a(2) is 2...
> Best,
> E.
>
> Le 19 oct. 2010 à 16:25, "Alexander P-sky" <apovolot at gmail.com> a
> écrit :
>
>> Hi Eric,
>>
>>> I think this is a permutation of the naturals.
>> Are you artificially (in my view) prepending
>> 1,2,3,4
>> in order to make it be permutation of the naturals ?
>>
>> Shouldn't the sequence really start with 5 instead ?
>>
>> ARP
>> ==========================================
>> On 10/19/10, Eric Angelini <Eric.Angelini at kntv.be> wrote:
>>> Hello SeqFans,
>>>
>>>
>>>
>>> This is (I guess) the lexicographically first sequence
>>>
>>> with a(1)=1 and a(n-1)+a(n)= a palindrome number (see
>>>
>>> http://www.research.att.com/~njas/sequences/A002113)
>>>
>>>
>>>
>>> S = 1,2,3,4,5,6,16,17,27,28,38,39,49,50,52,14,8,25,19,36,
>>>
>>> 30,47,41,58,43,12,10,23,21,34,32,45,54,57,13,20,24,31,35,
>>>
>>> 42,46,53,48,7,15,18,26,29,37,40,59,62,69,72,79,22,11,33,44,
>>>
>>> 55,56,65,66,75,76,85,86,95,96,...
>>>
>>>
>>>
>>> I think this is a permutation of the naturals.
>>>
>>>
>>>
>>> Best,
>>>
>>> É.
>>>
>>> [Next week I'll compute the similar sequence T, where
>>>
>>> a(n)+n = palindrome]
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