OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..20000
FORMULA
a(n) = min { j >= 0 : A316774(j) = n }.
EXAMPLE
a(4) = 4 because A316774(j) = 4 for j in {4,7,12,13,36,49,55} with minimal element 4.
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 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Alois P. Heinz, Jul 18 2018
STATUS
approved