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%I #3 Mar 30 2012 18:52:00
%S 3,6,4,8,8,16,24,48,88,176,344,688,1368,2736,5464,10928,21848,43696,
%T 87384,174768,349528,699056,1398104,2796208,5592408,11184816,22369624,
%U 44739248,89478488,178956976,357913944,715827888,1431655768,2863311536,5726623064
%N Jacobsthal numbers A001045 alternatingly incremented by 3 and 5.
%F a(2n+1) = 2*a(2n).
%F a(n) = A153643(n)+A010684(n).
%F a(n+2) = 4*A128209(n).
%F a(n) = 2*a(n-1)+a(n-2)-2*a(n-3). G.f.: (3-11x^2)/((1-x)(1+x)(1-2x)). [_R. J. Mathar_, Jan 23 2009]
%K nonn,easy
%O 0,1
%A _Paul Curtz_, Jan 17 2009
%E Edited and extended by _R. J. Mathar_, Jan 23 2009