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%I #4 Mar 18 2020 23:02:30
%S 3,4,3,2,3,3,3,4,3,3,4,3,2,3,3,2,3,4,3,3,3,2,3,3,3,4,3,2,3,3,2,3,3,3,
%T 4,3,3,4,3,2,3,3,3,4,3,3,3,2,3,3,2,3,4,3,3,4,3,2,3,3,3,4,3,3,4,3,2,3,
%U 3,2,3,3,3,4,3,3,3,2,3,4,3,3,4,3,2,3,3
%N First sums of the Kolakoski sequence A000002.
%F a(n) = A000002(n) + A000002(n + 1).
%t kolagrow[q_]:=If[Length[q]<2,Take[{1,2},Length[q]+1],Append[q,Switch[{q[[Length[Split[q]]]],q[[-2]],Last[q]},{1,1,1},0,{1,1,2},1,{1,2,1},2,{1,2,2},0,{2,1,1},2,{2,1,2},2,{2,2,1},1,{2,2,2},1]]]
%t kol[n_Integer]:=Nest[kolagrow,{1},n-1];
%t Table[kol[n][[-1]]+kol[n+1][[-1]],{n,30}]
%Y Positions of 3's are A054353.
%Y Positions of 2's are A074262.
%Y Positions of 4's are A074263.
%Y The number of runs in the first n terms of A000002 is A156253(n).
%Y Even-indexed terms are A332273 (without the first term).
%Y Odd-indexed terms are A332875.
%Y Cf. A000002, A001462, A013947, A013948, A088568, A156728, A288605, A296658, A329315, A329316, A329317, A329362.
%K nonn
%O 1,1
%A _Gus Wiseman_, Mar 18 2020
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