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A262904 If n = A259934(k) then a(n) = k, otherwise largest k such that A259934(k) is an ancestor of n in a tree generated by edge-relation A049820(child) = parent.

%I A262904 #11 Oct 11 2015 10:54:34
%S A262904 0,0,1,0,0,0,2,0,0,2,2,2,3,2,2,2,2,2,4,2,2,2,5,2,2,5,5,2,5,2,6,2,5,2,
%T A262904 7,2,2,2,7,2,5,2,8,2,7,2,9,2,7,9,7,2,9,2,10,2,7,2,11,2,7,2,12,2,2,2,
%U A262904 11,2,12,2,13,2,7,2,13,2,13,2,14,2,13,13,14,13,7,13,14,13,13,13,15,13,14,13,16,13,7,13,14,13,13,13,17,13,7,13,18,13,7,13,17,13,17,13,19,13,17,13,20,13,7,21
%N A262904 If n = A259934(k) then a(n) = k, otherwise largest k such that A259934(k) is an ancestor of n in a tree generated by edge-relation A049820(child) = parent.
%H A262904 Antti Karttunen, <a href="/A262904/b262904.txt">Table of n, a(n) for n = 0..32767</a>
%F A262904 If A262693(n) = 1 then a(n) = A262694(n) [i.e., when n = A259934(k), a(n) = k], otherwise a(n) = a(A049820(n)).
%F A262904 a(n) = A262694(A262679(n)).
%F A262904 Other identities. For all n >= 0:
%F A262904 a(A262896(n)) = n. [This sequence works as a left inverse for injection A262896.]
%o A262904 (Scheme, two variants)
%o A262904 (definec (A262904 n) (cond ((= 1 (A262693 n)) (A262694 n)) (else (A262904 (A049820 n)))))
%o A262904 (define (A262904 n) (A262694 (A262679 n)))
%Y A262904 Cf. A049820, A262679, A262693, A262694, A262896, A262905, A262906, A262907.
%K A262904 nonn
%O A262904 0,7
%A A262904 _Antti Karttunen_, Oct 07 2015