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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.

%I A260438 #17 Aug 02 2015 17:53:38
%S A260438 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,
%T A260438 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,
%U A260438 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
%N 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.
%C A260438 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.
%H A260438 Antti Karttunen, <a href="/A260438/b260438.txt">Table of n, a(n) for n = 1..10003</a>
%F A260438 Other identities. For all n >= 1:
%F A260438 a(A000959(n)) = n.
%F A260438 a(A219178(n)) = n.
%F A260438 a(2n) = 1. [All even numbers are removed at the stage one of the sieve.]
%F A260438 a(A016969(n)) = 2.
%F A260438 a(A258016(n)) = 3.
%F A260438 a(A260440(n)) = 4.
%F A260438 A255545(a(n), A260429(n)) = n.
%F A260438 For all n >= 2, A255551(a(n), A260439(n)) = n.
%o A260438 (Scheme)
%o A260438 (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.
%Y A260438 Cf. A000959, A050505, A109497, A145649, A219178, A255543, A255545, A255551.
%Y A260438 Cf. also A260429, A260439 (corresponding column indices).
%Y A260438 Cf. A055396, A260738 for row indices to other arrays similar to A255545.
%K A260438 nonn
%O A260438 1,3
%A A260438 _Antti Karttunen_, Jul 29 2015