%N a(n) = index of n in A266117 or 0 if n is not present in that sequence.
%C It is conjectured that A266117 is not just injective, but also surjective on N, i.e., that it is a true permutation of natural numbers. In that case also this sequence is a true permutation, and no hypothetical zero-values are ever needed.
%H Antti Karttunen, <a href="/A266118/b266118.txt">Table of n, a(n) for n = 1..12634</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%o (Scheme, with code for A266117 defined with defineperm1-macro also required)
%o (define (A266118 n) (A266117 (- n))) ;; This returns inverse values of A266117 from its hidden cache.
%Y Inverse: A266117 (with provisions, see comment section).
%A _Antti Karttunen_, Dec 22 2015