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A260721 Half the difference between n-th odd Ludic and n-th Lucky number: a(1) = 0; a(n) = (A003309(n+1) - A000959(n))/2.

%I A260721 #6 Aug 10 2015 07:27:39
%S A260721 0,0,-1,-1,-1,-1,-2,-1,-3,-2,0,-1,-3,-2,-5,-3,-1,-1,1,2,1,-1,-1,1,2,2,
%T A260721 -3,-1,-1,4,4,3,1,5,3,4,-4,0,7,5,8,6,4,5,2,2,5,8,3,8,8,7,9,11,12,16,
%U A260721 14,15,11,16,16,15,19,17,16,18,20,15,14,14,16,12,11,12,18,19,21,15,15,11,13,13,15,19,20,15,18,23,24,23,28,27,27,27,20,23
%N A260721 Half the difference between n-th odd Ludic and n-th Lucky number: a(1) = 0; a(n) = (A003309(n+1) - A000959(n))/2.
%H A260721 Antti Karttunen, <a href="/A260721/b260721.txt">Table of n, a(n) for n = 1..10000</a>
%H A260721 <a href="/index/Si#sieve">Index entries for sequences generated by sieves</a>
%F A260721 a(1) = 0; a(n) = (A003309(n+1) - A000959(n))/2.
%F A260721 a(n) = A260722(n)/2.
%o A260721 (Scheme) (define (A260721 n) (if (= 1 n) 0 (/ (- (A003309 (+ 1 n)) (A000959 n)) 2)))
%Y A260721 Cf. A000959, A003309, A260722, A256488.
%K A260721 sign
%O A260721 1,7
%A A260721 _Antti Karttunen_, Aug 06 2015