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A316905 a(n) is the index of the first occurrence of n in A316774.

%I A316905 #26 Aug 28 2023 08:25:27
%S A316905 0,1,2,5,4,8,11,22,14,32,28,42,48,45,68,71,77,89,108,115,92,140,95,
%T A316905 149,216,268,194,260,310,254,263,340,362,257,295,277,298,476,346,431,
%U A316905 365,560,539,424,486,462,576,479,579,692,657,707,754,794,757,797,928
%N A316905 a(n) is the index of the first occurrence of n in A316774.
%H A316905 Alois P. Heinz, <a href="/A316905/b316905.txt">Table of n, a(n) for n = 0..20000</a>
%F A316905 a(n) = min { j >= 0 : A316774(j) = n }.
%e A316905 a(4) = 4 because A316774(j) = 4 for j in {4,7,12,13,36,49,55} with minimal element 4.
%p A316905 b:= proc() 0 end:
%p A316905 g:= proc(n) option remember; local t;
%p A316905       t:= `if`(n<2, n, b(g(n-1))+b(g(n-2)));
%p A316905       b(t):= b(t)+1; t
%p A316905     end:
%p A316905 a:= proc() local t, a; t, a:= -1, proc() -1 end;
%p A316905       proc(n) local h;
%p A316905         while a(n) = -1 do
%p A316905           t:= t+1; h:= g(t);
%p A316905           if a(h) = -1 then a(h):= t fi
%p A316905         od; a(n)
%p A316905       end
%p A316905     end():
%p A316905 seq(a(n), n=0..100);
%t A316905 b[_] = 0;
%t A316905 g[n_] := g[n] = Module[{t}, t = If[n < 2, n, b[g[n - 1]] + b[g[n - 2]]];       b[t] = b[t] + 1; t];
%t A316905 a[n_] := Module[{t = -1, a}, a[_] = -1; Module[{h}, While[a[n] == -1, t = t + 1; h = g[t]; If[a[h] == -1, a[h] = t]]; a[n]]];
%t A316905 Table[a[n], {n, 0, 100}] (* _Jean-François Alcover_, Aug 28 2023, after _Alois P. Heinz_ *)
%Y A316905 Cf. A316774, A316973, A316984, A330440 (a sorted version of this), A330447, A330448.
%K A316905 nonn,look
%O A316905 0,3
%A A316905 _Alois P. Heinz_, Jul 18 2018