Greedy Dragons

[David Wilson]

----- Original Message ----- 
From: "Hans Havermann" <hahaj at rogers.com>
To: "SeqFan" <seqfan at ext.jussieu.fr>
Sent: Thursday, September 26, 2002 8:43 PM
Subject: Greedy Dragons


> A065186
> 
> Sequence:  
> 1,3,5,2,4,6,8,10,7,9,11,13,15,12,14,16,18,20,17,19,21,23,25,22,24,26,28, 
> 30,27,29,31,33,35,32,34,36,38,40,37,39,41,43,45,42,44,46,48,50,47,49,51, 
> 53,55,52,54,56,58,60,57,59,61,63,65,62,64,66,68,70,67,69,71,73
> 
> Name: "Greedy Dragons" permutation of the natural numbers
> 
> A very complex description (comment), and formula... Isn't this  
> sequence just the smallest positive integer not already in sequence  
> with the absolute value of a(n)-a(n-1) prime? Cf. A055265.

Simpler still: a(n) = a(n-5)+5.