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%I #9 Nov 08 2013 13:46:48
%S 0,1,2,0,0,3,4,5,0,0,6,7,8,0,0,9,10,11,0,0,0,0,0,12,13,14,0,0,15,16,
%T 17,0,0,18,19,20,0,0,21,22,23,0,0,0,0,0,24,25,26,0,0,27,28,29,0,0,30,
%U 31,32,0,0,33,34,35,0,0,0,0,0,36,37,38,0,0,39,40,41
%N Inverse function for injection A219650.
%C a(0)=0; thereafter if n occurs as a term of A219650, a(n)=its position in A219650, otherwise zero. This works as an "inverse" function for A219650 in a sense that a(A219650(n)) = n for all n.
%H Antti Karttunen, <a href="/A230414/b230414.txt">Table of n, a(n) for n = 0..10079</a>
%F a(n) = A230412(n) * A230413(n).
%F a(n) = A230423(n)/2.
%o (Scheme)
%o (define (A230414 n) (* (A230412 n) (A230413 n)))
%Y Cf. A219650, A230423, A230424. A219658 gives the positions of zeros after the first one. Analogous sequence for binary system: A213714.
%K nonn
%O 0,3
%A _Antti Karttunen_, Oct 31 2013
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