%I
%S 0,1,1,2,2,3,4,3,7,6,4,5,8,10,5,6,7,11,8,12,14,10,18,9,9
%N Consider the numbers on the xaxis in the spiral shown in A274641; a(n) is the distance from n to the origin, or 1 if n never appears on the xaxis.
%C It is conjectured that every nonnegative number appears on the xaxis exactly once.
%C a(n) is also the distance to the origin from the point n+1 on the xaxis in A274640.
%C Needs a large bfile: it will be interesting to see how irregular this sequence is.
%e The portion of the xaxis near 0 is:
%e ... 14 6 5 4 2 0 1 3 7 10 11 ...
%e and we see that both 1 and 2 are at distance 1 from 0. So a(1) = a(2) = 1.
%Y Cf. A274640, A274641.
%Y The positive and negative xaxes are given in A274924 and A274928.
%K nonn,more
%O 0,4
%A _N. J. A. Sloane_, Mar 11 2019
