%I #4 Aug 16 2016 20:46:29
%S 1,4,5,6,2,3,9,12,13,14,8,15,7,18,11,20,10,26,17,25,19,27,30,21,23,29,
%T 31,22,16,41,45,32,34,24,38,36,39,33,37,46,43,28,35,42,56,55,57,50,51,
%U 62,53,60,64,71,58,69,40,74,68,54,63,80,65,82,73,47,87
%N Numbers on the North-South axis of A274640 in order of appearance.
%C Conjectured to be a permutation of the natural numbers.
%H Alois P. Heinz, <a href="/A276036/b276036.txt">Table of n, a(n) for n = 1..2000</a>
%Y Cf. A274640.
%Y Alternate terms of A274926 and A274930 (starting with a single 1).
%K nonn
%O 1,2
%A _Alois P. Heinz_, Aug 16 2016