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 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). 6
 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 (list; graph; refs; listen; history; text; internal format)
 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 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: A073312 A166514 A246024 * A160588 A081171 A062778 Adjacent sequences:  A278526 A278527 A278528 * A278530 A278531 A278532 KEYWORD nonn AUTHOR Antti Karttunen, Nov 23 2016 STATUS approved

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Last modified September 18 05:32 EDT 2019. Contains 327165 sequences. (Running on oeis4.)