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%I #18 Aug 27 2024 03:11:50
%S 1,1,2,2,4,5,8,12,19,29,45,70,109,170,265,414,646,1009,1575,2460,3840,
%T 5997,9364,14622,22833,35654,55676,86940,135762,211998,331047,516946,
%U 807239,1260545,1968408,3073772,4799858,7495231,11704199,18276724
%N a(0) = 1, a(1) = 1 and for n >= 2, a(n) = floor(4 * a(n-2) * a(n-1) / (a(n-2) + a(n-1))).
%H Harvey P. Dale, <a href="/A093335/b093335.txt">Table of n, a(n) for n = 0..1000</a>
%e a(5) = 5 because a(5) = floor(4*a(3)*a(4)/(a(3)+a(4))) = floor(4*2*4/(2+4)) = floor(32/6) = 5.
%t nxt[{a_,b_}]:={b,Floor[2*HarmonicMean[{a,b}]]}; Join[{1},Transpose[ NestList[ nxt,{1,2},40]][[1]]] (* _Harvey P. Dale_, Mar 04 2015 *)
%Y Cf. A093333, A093332.
%K easy,nonn
%O 0,3
%A Robert A. Stump (rstump_2004(AT)yahoo.com), Apr 25 2004
%E Definition corrected by _Jason Yuen_, Aug 27 2024