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A permutation of the natural numbers related to Goldbach conjecture.
4

%I #13 Aug 04 2015 22:25:37

%S 1,2,3,4,5,6,7,9,8,11,10,13,14,12,15,17,18,16,19,21,20,23,24,25,22,27,

%T 26,29,30,28,31,33,32,35,36,39,38,42,37,34,40,43,45,41,44,48,49,46,51,

%U 47,50,53,56,57,52,55,54,60,58,63,59,65,62,66,61,70,67,69,68,71,72,73,75,74,77,78,76,81,80,84

%N A permutation of the natural numbers related to Goldbach conjecture.

%C a(n) = if n <= 2 then n else A187085(n-2)/2;

%C for n > 2: a(n+1) = a(n) + (A187072(n) - A187072(n-2)) / 2.

%H Reinhard Zumkeller, <a href="/A187098/b187098.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%H <a href="/index/Go#Goldbach">Index entries for sequences related to Goldbach conjecture</a>

%o (Haskell)

%o a187098 n = a187098_list !! (n-1)

%o a187098_list = 1 : 2 : map (`div` 2) a187085_list

%Y Cf. A065306, A187099 (inverse).

%Y Cf. A187085, A187072.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Mar 04 2011