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 A260438 Row index to A255545: If n is k-th Lucky number then a(n) = k, otherwise a(n) = number of the stage where n is removed in Lucky sieve. 12
 1, 1, 2, 1, 2, 1, 3, 1, 4, 1, 2, 1, 5, 1, 6, 1, 2, 1, 3, 1, 7, 1, 2, 1, 8, 1, 4, 1, 2, 1, 9, 1, 10, 1, 2, 1, 11, 1, 3, 1, 2, 1, 12, 1, 5, 1, 2, 1, 13, 1, 14, 1, 2, 1, 6, 1, 4, 1, 2, 1, 3, 1, 15, 1, 2, 1, 16, 1, 17, 1, 2, 1, 18, 1, 19, 1, 2, 1, 20, 1, 3, 1, 2, 1, 7, 1, 21, 1, 2, 1, 4, 1, 22, 1, 2, 1, 5, 1, 23, 1, 2, 1, 3, 1, 24, 1, 2, 1, 8, 1, 25, 1, 2, 1, 26, 1, 6, 1, 2, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS For n >= 2 this works also as a row index to array A255551 (which does not contain 1) and when restricted to unlucky numbers, A050505, also as a row index to array A255543. LINKS Antti Karttunen, Table of n, a(n) for n = 1..10003 FORMULA Other identities. For all n >= 1: a(A000959(n)) = n. a(A219178(n)) = n. a(2n) = 1. [All even numbers are removed at the stage one of the sieve.] a(A016969(n)) = 2. a(A258016(n)) = 3. a(A260440(n)) = 4. A255545(a(n), A260429(n)) = n. For all n >= 2, A255551(a(n), A260439(n)) = n. PROG (Scheme) (define (A260438 n) (cond ((not (zero? (A145649 n))) (A109497 n)) ((even? n) 1) (else (let searchrow ((row 2)) (let searchcol ((col 1)) (cond ((>= (A255543bi row col) n) (if (= (A255543bi row col) n) row (searchrow (+ 1 row)))) (else (searchcol (+ 1 col))))))))) ;; Code for A255543bi given in A255543. CROSSREFS Cf. A000959, A050505, A109497, A145649, A219178, A255543, A255545, A255551. Cf. also A260429, A260439 (corresponding column indices). Cf. A055396, A260738 for row indices to other arrays similar to A255545. Sequence in context: A243546 A243554 A263111 * A112197 A112198 A326850 Adjacent sequences:  A260435 A260436 A260437 * A260439 A260440 A260441 KEYWORD nonn AUTHOR Antti Karttunen, Jul 29 2015 STATUS approved

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Last modified August 25 03:03 EDT 2019. Contains 326318 sequences. (Running on oeis4.)