%I #16 May 22 2014 03:31:33
%S 1,2,3,6,10,17,30,53,95,171,310,564,1036,1918,3574,6691,12566,23653,
%T 44610,84309,159698,303253,577352,1102121,2109448,4047967,7787277,
%U 15015347,29011671,56150867,108825599,211127246,409886210,796134319,1546848744,3006198333,5843799964
%N The middle point of row n in binary beanstalk related sequences A179016, A218602, A218616, A233270, A233271.
%C a(n) points to the center of each palindromic row/subrange of A233270, and to the lower position nearest to the center, if the length of range is even.
%C For all n, A218602(a(n)) = a(n) + (1-A000035(A213709(n-1))).
%F a(n) = floor((A213710(n-1) + A218600(n)) / 2).
%F a(n) = A218600(n-1) + ceiling((A213709(n-1)/2)).
%o (MIT/GNU Scheme, two alternative versions)
%o (define (A233268 n) (floor->exact (/ (+ (A213710 (- n 1)) (A218600 n)) 2)))
%o (define (A233268 n) (+ (A218600 (- n 1)) (ceiling->exact (/ (A213709 (- n 1)) 2))))
%Y Cf. A213709, A213710, A218600, A234018, A234019, A234020.
%Y Cf. also A179016, A218602, A218616, A233270, A233271.
%K nonn
%O 1,2
%A _Antti Karttunen_, Dec 29 2013