A256478 a(0) = 0; and for n >= 1, if A079559(n) = 1, then a(n) = 1 + a(A213714(n)-1), otherwise a(n) = a(A234017(n)).

0, 1, 1, 2, 2, 1, 2, 3, 3, 2, 2, 3, 1, 2, 3, 4, 4, 3, 3, 3, 2, 2, 4, 2, 3, 3, 4, 1, 2, 3, 4, 5, 5, 4, 4, 4, 3, 3, 4, 3, 3, 3, 5, 2, 2, 4, 3, 4, 2, 4, 5, 3, 3, 2, 3, 4, 4, 5, 1, 2, 3, 4, 5, 6, 6, 5, 5, 5, 4, 4, 5, 4, 4, 4, 5, 3, 3, 4, 4, 4, 3, 4, 6, 3, 3, 3, 3, 5, 5, 4, 2, 2, 4, 3, 5, 3, 4, 5, 6, 2, 4, 4, 4, 5, 3, 4, 3, 3, 2, 5, 5, 3, 6, 2, 4, 4, 3, 4, 5, 5, 6, 1, 2, 3, 4, 5, 6, 7, 7

Offset

0,4

Comments

a(n) tells how many nonzero terms of A005187 are encountered when traversing toward the root of binary tree A233276, starting from the node containing n. This count includes both n (in case it is a term of A005187) and 1 (but not 0). See also comments in A256479 and A256991.

The 1's (seem to) occur at positions given by A000325.

Links

Antti Karttunen, Table of n, a(n) for n = 0..16384

Formula

a(0) = 0; and for n >= 1, if A079559(n) = 1, then a(n) = 1 + a(A213714(n)-1), otherwise a(n) = a(A234017(n)).

a(n) = A000120(A233277(n)). [Binary weight of A233277(n).]

Other identities and observations. For all n >= 1:

a(n) = 1 + A257248(n) = 1 + A080791(A233275(n)).

a(n) = A070939(n) - A256479(n).

a(n) >= A255559(n).

Prog

(Scheme, with memoization-macro definec)
(definec (A256478 n) (if (< n 1) n (+ (A079559 n) (A256478 (if (zero? (A079559 n)) (A234017 n) (+ -1 (A213714 n)))))))
;; Alternative definitions:
(define (A256478 n) (A000120 (A233277 n)))
(define (A256478 n) (if (zero? n) n (+ 1 (A080791 (A233275 n)))))

Crossrefs

One more than A257248.

Cf. A000120, A000325, A005187, A070939, A079559, A080791, A213714, A234017, A233275, A233276, A233277, A255559, A256479, A256991.

Sequence in context: A167489 A256790 A337225 * A356245 A106638 A329400

Adjacent sequences: A256475 A256476 A256477 * A256479 A256480 A256481

Keyword

nonn

Author

Antti Karttunen, Apr 15 2015

Status

approved