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

0, 1, 2, 5, 4, 8, 11, 22, 14, 32, 28, 42, 48, 45, 68, 71, 77, 89, 108, 115, 92, 140, 95, 149, 216, 268, 194, 260, 310, 254, 263, 340, 362, 257, 295, 277, 298, 476, 346, 431, 365, 560, 539, 424, 486, 462, 576, 479, 579, 692, 657, 707, 754, 794, 757, 797, 928

Offset: 0

Author

Alois P. Heinz, Jul 18 2018

Keywords

• nonn
• look

Examples

			a(4) = 4 because A316774(j) = 4 for j in {4,7,12,13,36,49,55} with minimal element 4.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..20000

Crossrefs

Cf. A316774, A316973, A316984, A330440 (a sorted version of this), A330447, A330448.

Programs

Maple

b:= proc() 0 end:
g:= proc(n) option remember; local t;
      t:= `if`(n<2, n, b(g(n-1))+b(g(n-2)));
      b(t):= b(t)+1; t
    end:
a:= proc() local t, a; t, a:= -1, proc() -1 end;
      proc(n) local h;
        while a(n) = -1 do
          t:= t+1; h:= g(t);
          if a(h) = -1 then a(h):= t fi
        od; a(n)
      end
    end():
seq(a(n), n=0..100);

Mathematica

b[_] = 0;
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];
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]]];
Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Aug 28 2023, after Alois P. Heinz *)

Formula

a(n) = min { j >= 0 : A316774(j) = n }.