A233268 - OEIS

A233268

The middle point of row n in binary beanstalk related sequences A179016, A218602, A218616, A233270, A233271.

1, 2, 3, 6, 10, 17, 30, 53, 95, 171, 310, 564, 1036, 1918, 3574, 6691, 12566, 23653, 44610, 84309, 159698, 303253, 577352, 1102121, 2109448, 4047967, 7787277, 15015347, 29011671, 56150867, 108825599, 211127246, 409886210, 796134319, 1546848744, 3006198333, 5843799964

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OFFSET

1,2

COMMENTS

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.

For all n, A218602(a(n)) = a(n) + (1-A000035(A213709(n-1))).

LINKS

Table of n, a(n) for n=1..37.

FORMULA

a(n) = floor((A213710(n-1) + A218600(n)) / 2).

a(n) = A218600(n-1) + ceiling((A213709(n-1)/2)).

PROG

(MIT/GNU Scheme, two alternative versions)

(define (A233268 n) (floor->exact (/ (+ (A213710 (- n 1)) (A218600 n)) 2)))

(define (A233268 n) (+ (A218600 (- n 1)) (ceiling->exact (/ (A213709 (- n 1)) 2))))

CROSSREFS

Cf. A213709, A213710, A218600, A234018, A234019, A234020.