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a(1) = 1, a(n+1) = a(n)-n if a(n) > n else a(n+1) = a(n) + n.
5

%I #15 Aug 23 2014 13:08:35

%S 1,2,4,1,5,10,4,11,3,12,2,13,1,14,28,13,29,12,30,11,31,10,32,9,33,8,

%T 34,7,35,6,36,5,37,4,38,3,39,2,40,1,41,82,40,83,39,84,38,85,37,86,36,

%U 87,35,88,34,89,33,90,32,91,31,92,30,93,29,94,28,95,27,96,26,97,25,98,24,99

%N a(1) = 1, a(n+1) = a(n)-n if a(n) > n else a(n+1) = a(n) + n.

%C Let (3^k-1)/2 = r then a((3^k-1)/2) = a(r) = 1 and a(r-1) = r. Geometrical interpretation. The sequence is obtained by the following rule: A point moves on the positive number line with the rule that in every step it has to move one unit more than the previous step and with the aim that it is to be as close to 0 as possible but on the positive side.

%C a(A003462(n)) = 1. - _Reinhard Zumkeller_, Jan 31 2013

%H Reinhard Zumkeller, <a href="/A085059/b085059.txt">Table of n, a(n) for n = 1..10000</a>

%t RecurrenceTable[{a[1]==1,a[n+1]==If[a[n]>n,a[n]-n , a[n]+n]}, a[n], {n,80}] (* _Harvey P. Dale_, May 11 2011 *)

%o (Haskell)

%o a085059 n = a085059_list !! (n-1)

%o a085059_list = 1 : f 1 1 where

%o f v w = y : f (v + 1) y where

%o y = if w > v then w - v else w + v

%o -- _Reinhard Zumkeller_, Jan 31 2013

%Y Cf. A005132.

%Y Equals 1+A008344(n).

%Y Cf. A046901.

%K nonn,easy

%O 1,2

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 27 2003

%E More terms from _Sam Alexander_, Oct 20 2003