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%I #9 Mar 30 2022 06:11:40
%S 0,0,1,0,2,0,2,1,2,0,6,0,3,0,6,0,4,0,6,0,5,1,7,2,6,2,7,1,8,0,8,0,8,0,
%T 11,0,9,1,10,0,11,0,11,0,11,0,14,3,12,0,13,0,13,0,15,0,15,0,15,0,16,0,
%U 18,0,16,0,17,0,17,0,19,0,18,2,19,0,19,0,20,2
%N a(n) = A037237(n-1) - A281434(n).
%C It appears that this sequence has an infinite number of zeros, i.e., A281434(n) agrees with A037237(n-1) at an infinite number of indices; also, it seems that a(n) = O(n).
%t With[{m = 20}, Table[(4 n + 3 n^2 + 2 n^3)/3, {n, m}] - Length /@ Rest[NestList[Expand[D[#, x]] &, x^x^x, m]]]
%Y Cf. A037237, A281434.
%K nonn
%O 1,5
%A _Vladimir Reshetnikov_, Mar 29 2022