

A065674


Positions of the elements of the quasicyclic group Z+(2a+1)/(2^b) [a > 0 and a < 2^(b1), b > 0] at the ]0,1[ side of the Stern Brocot Tree (A007305/A007306).


7



1, 4, 7, 64, 10, 13, 127, 16384, 67, 79, 46, 49, 112, 124, 32767, 1073741824, 2050, 262, 139, 151, 2560, 352, 766, 769, 415, 3583, 232, 244, 505, 4093, 2147483647, 4611686018427387904, 4194307, 32776, 16447, 16639, 1057, 34816, 571, 583, 310
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..41.
Index entries for sequences related to Stern's sequences


EXAMPLE

The fraction 1/2 is at the root (position 1), 1/4 is the left child of its left child, in the position 4 (when the tree is traversed in lefttoright, breadthfirst fashion), while 3/4 is the right child of the right child of the root (pos. 7), 1/8 is at the position 64 (6 steps down the left branch from the root) and 3/8 is the right child of the left child of the root, at the position 10, etc.


MAPLE

QuasiCyclics2_pos_in_0_1_SB_tree := proc(t) local num, den; den := 2^(1+floor_log_2(t)); num := (2*(t(den/2)))+1; RETURN(frac2position_in_0_1_SB_tree(num/den)); end;


CROSSREFS

Permutation of A065810. Cf. A065658, A065674, A065675.
[seq(QuasiCyclics2_pos_in_0_1_SB_tree(j), j=1..128)],
Sequence in context: A261672 A013467 A060413 * A135790 A253202 A156474
Adjacent sequences: A065671 A065672 A065673 * A065675 A065676 A065677


KEYWORD

nonn


AUTHOR

Antti Karttunen, Nov 22 2001


STATUS

approved



