A278529 a(n) = one-based position in the round in which n is removed in the Flavius sieve, 0 if n is never removed (when n is one of the terms of A000960).

0, 1, 0, 2, 1, 3, 0, 4, 1, 5, 2, 6, 0, 7, 1, 8, 3, 9, 0, 10, 2, 11, 4, 12, 1, 13, 0, 14, 5, 15, 1, 16, 3, 17, 6, 18, 2, 19, 0, 20, 7, 21, 1, 22, 4, 23, 8, 24, 0, 25, 2, 26, 9, 27, 3, 28, 5, 29, 10, 30, 1, 31, 0, 32, 11, 33, 1, 34, 6, 35, 12, 36, 2, 37, 4, 38, 13, 39, 0, 40, 7, 41, 14, 42, 3, 43, 1, 44, 15, 45, 0, 46, 8, 47, 16, 48, 5, 49, 2, 50, 17, 51, 1, 52

Offset

1,4

Comments

a(n) = index of the column where n is located in array A278507, 0 if n does not occur there (when n is one of the terms of A000960).

Links

Antti Karttunen, Table of n, a(n) for n = 1..10707

Index entries for sequences related to the Josephus Problem

Formula

For n > 1, a(A100287(n)) = 1.

Prog

(Scheme)
;; Very crude. Find it with two nested loops. (Maybe a closed form exists?)
(define (A278529 n) (cond ((not (zero? (A278169 n))) 0) ((even? n) (/ n 2)) (else (let searchrow ((row 2)) (let searchcol ((col 1)) (cond ((>= (A278507bi row col) n) (if (= (A278507bi row col) n) col (searchrow (+ 1 row)))) (else (searchcol (+ 1 col)))))))))
;; Code for A278507bi given in A278507.

Crossrefs

One less than A278539.

Cf. A278507, A278528 (the other index).

Cf. A000960 (positions of zeros), A100287 (positions of 1's, after the initial 1).

Sequence in context: A350941 A166514 A246024 * A160588 A195084 A081171

Adjacent sequences: A278526 A278527 A278528 * A278530 A278531 A278532

Keyword

nonn

Author

Antti Karttunen, Nov 23 2016

Status

approved