A233274 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.

0, 0, -1, 0, 0, 0, 0, 1, 2, 4, 8, 13, 22, 38, 68, 125, 232, 429, 786, 1428, 2578, 4645, 8364, 15064, 27145, 48990, 88736, 161813, 298001, 555451, 1048207, 1999608, 3844722, 7425094, 14356699, 27722560, 53374986

Offset: 1

Author

Antti Karttunen, Jan 01 2014

Keywords

• sign

Comments

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).

Links

• A. Karttunen, Sequences A233271 and A218616 compared with OEIS Plot2-script

Crossrefs

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

Programs

Scheme

(define (A233274 n) (if (< n 3) 0 (- (+ -1 (ceiling->exact (/ (A213709 (- n 1)) 2))) (A226060 (- n 2)))))
(define (A233274v2 n) (if (< n 2) 0 (- (A233268 n) (+ (A218600 (- n 1)) (A226060 (- n 2))) 1)))

Formula

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)