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.

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, 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, 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

Offset: 0

Author

Antti Karttunen, Oct 07 2015

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..32767

Crossrefs

Cf. A049820, A262679, A262693, A262694, A262896, A262905, A262906, A262907.

Formula

If A262693(n) = 1 then a(n) = A262694(n) [i.e., when n = A259934(k), a(n) = k], otherwise a(n) = a(A049820(n)).

a(n) = A262694(A262679(n)).

Other identities. For all n >= 0:

a(A262896(n)) = n. [This sequence works as a left inverse for injection A262896.]