%I #9 May 17 2013 17:35:25
%S 4,5,7,8,10,12,13,14,15,16,17,19,21,22,23,24,25,27,28,29,30,31,32,33,
%T 34,35,37,39,40,41,42,43,44,45,46,47,49,50,51,52,53,54,55,56,57,58,59,
%U 60,62,63,65,66,67,68,69,70,71,72,73,74,76,77,78,79,80,81,82,83,84,85,86
%N Construct sequences P,Q,R by the rules: Q = first differences of P, R = second differences of P, P starts with 1,3,9, Q starts with 2,6, R starts with 4; at each stage the smallest number not yet present in P,Q,R is appended to R. Sequence gives R.
%C In contrast to A225376-A225378, here it is not required (and not true) that each number should appear just once in P union Q union R. On the other hand, again in contrast to A225376-A225378, here it is obvious that P, Q, R are infinite.
%C The first three numbers that are repeated are 284, 2074, 3500, which appear in both P and Q. There may be no others. Of course R is disjoint from P and Q, by definition.
%p See A225385.
%Y Cf. A225385, A225386, A005228, A030124, A037257, A225376, A225377, A225378.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, May 15 2013