%I #8 Jan 14 2014 12:14:33

%S 0,0,-1,0,0,0,0,1,2,4,8,13,22,38,68,125,232,429,786,1428,2578,4645,

%T 8364,15064,27145,48990,88736,161813,298001,555451,1048207,1999608,

%U 3844722,7425094,14356699,27722560,53374986

%N Relative offsets from the middle point of each row of A233271 & A218616 to the first point where the former exceeds the latter, which apart of case a(3)=-1 is always left of or at the middle point.

%C The sequence tells how many positions to the left of center of each row/subrange (of irregular tables like A233270, central point given by A233268) the sequences A233271 and A218616 cross each other (please see the linked graph).

%H A. Karttunen, <a href="https://oeis.org/plot2a?name1=A233271&amp;name2=A218616&amp;tform1=untransformed&amp;tform2=untransformed&amp;shift=0&amp;radiop1=matp&amp;drawlines=true"> Sequences A233271 and A218616 compared with OEIS Plot2-script</a>

%F a(1)=a(2)=0, and for n > 2, a(n) = ⌈(A213709(n-1)/2)⌉ - A226060(n-2) - 1. Where ⌈x⌉ stands for ceiling(x)

%o (Scheme)

%o (define (A233274 n) (if (< n 3) 0 (- (+ -1 (ceiling->exact (/ (A213709 (- n 1)) 2))) (A226060 (- n 2)))))

%o (define (A233274v2 n) (if (< n 2) 0 (- (A233268 n) (+ (A218600 (- n 1)) (A226060 (- n 2))) 1)))

%Y Cf. A234020, A213709, A218600, A226060, A233268, A179016, A218616, A233270.

%K sign

%O 1,9

%A _Antti Karttunen_, Jan 01 2014