A330588 a(n) is the first index m such that A330439(m) = n.

0, 3, 6, 13, 21, 23, 27, 33, 46, 67, 81, 104, 107, 114, 129, 166, 169, 172, 193, 261, 267, 276, 287, 311, 373, 430, 457, 478, 485, 590, 596, 656, 691, 768, 789, 796, 873, 941, 969, 1047, 1093, 1149, 1170, 1239, 1303, 1349, 1491, 1533, 1555, 1567, 1805, 1808

Offset: 1

Author

Alois P. Heinz, Dec 18 2019

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..16000

Crossrefs

Row n=1 of A330587.

Cf. A316774, A330439.

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:
f:= proc(n) option remember; b(g(n)) end:
a:= proc() local l, t; t, l:= -1, proc() -1 end;
      proc(k) local h;
        while l(k)<0 do t:= t+1; h:= f(t);
          if l(h)<0 then l(h):= t fi
        od: l(k)
      end
    end():
seq(a(n), n=1..60);

Mathematica

b[_] = 0;
g[n_] := g[n] = Module[{t}, t = If[n < 2, n, b[g[n-1]] + b[g[n-2]]]; b[t]++; t];
f[n_] := f[n] = b[g[n]];
A[n_, k_] := Module[{l, t = -1, h}, l[_] = {}; While[Length[l[k]] < n, t++; h = f[t]; AppendTo[l[h], t]]; l[k][[n]]];
a[k_] := A[1, k];
Table[a[n], {n, 1, 60}] (* Jean-François Alcover, Dec 13 2023, after Alois P. Heinz *)