A285725 - OEIS

A285725

a(1) = 0; for n > 1, a(n) = A252735(n) - A000035(n).

0, 0, 0, 0, 1, 1, 2, 0, 0, 2, 3, 1, 4, 3, 1, 0, 5, 1, 6, 2, 2, 4, 7, 1, 1, 5, 0, 3, 8, 2, 9, 0, 3, 6, 2, 1, 10, 7, 4, 2, 11, 3, 12, 4, 1, 8, 13, 1, 2, 2, 5, 5, 14, 1, 3, 3, 6, 9, 15, 2, 16, 10, 2, 0, 4, 4, 17, 6, 7, 3, 18, 1, 19, 11, 1, 7, 3, 5, 20, 2, 0, 12, 21, 3, 5, 13, 8, 4, 22, 2, 4, 8, 9, 14, 6, 1, 23, 3, 3, 2, 24, 6, 25, 5, 2, 15, 26, 1, 27, 4, 10, 3

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OFFSET

1,7

COMMENTS

Consider the binary tree illustrated in A005940: If we start from any n, computing successive iterations of A252463 until 1 is reached (i.e., we are traversing level by level towards the root of the tree, starting from that vertex of the tree where n is located at), a(n) gives the number of odd numbers > 1 encountered on the path after the initial n, that is, both the final 1 and also the starting n (if it was odd) are excluded from the count.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..8192

FORMULA

a(1) = 0; for n > 1, a(n) = A252735(n) - A000035(n).

PROG

(Scheme) (define (A285725 n) (if (= 1 n) 0 (- (A252735 n) (A000035 n))))

CROSSREFS

Cf. A000035, A005940, A252463, A252735, A285726.

Sequence in context: A340378 A274575 A203994 * A215889 A195022 A146095

Adjacent sequences: A285722 A285723 A285724 * A285726 A285727 A285728

KEYWORD

nonn

AUTHOR

Antti Karttunen, Apr 25 2017

STATUS

approved