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A274996 a(n) = F(F(F(n))) mod F(F(n)), where F = Fibonacci = A000045.

%I A274996 #15 Nov 14 2020 09:49:59
%S A274996 0,0,0,1,0,5,232,987,1,5,1,0,
%T A274996 2211236406303914545699412969744873993387956988652,
%U A274996 2211236406303914545699412969744873993387956988653,139583862445
%N A274996 a(n) = F(F(F(n))) mod F(F(n)), where F = Fibonacci = A000045.
%H A274996 Alois P. Heinz, <a href="/A274996/b274996.txt">Table of n, a(n) for n = 1..19</a>
%F A274996 a(n) = A058051(n) mod A007570(n).
%p A274996 F:= proc(n) local r, M, p; r, M, p:=
%p A274996       <<1|0>, <0|1>>, <<0|1>, <1|1>>, n;
%p A274996       do if irem(p, 2, 'p')=1 then r:=
%p A274996         `if`(nargs=1, r.M, r.M mod args[2]) fi;
%p A274996          if p=0 then break fi; M:=
%p A274996         `if`(nargs=1, M.M, M.M mod args[2])
%p A274996       od; r[1, 2]
%p A274996     end:
%p A274996 a:= n-> (h-> F(h$2))(F(F(n))):
%p A274996 seq(a(n), n=1..15);
%Y A274996 Cf. A000045, A007570, A058051, A263101, A263112, A338889.
%K A274996 nonn
%O A274996 1,6
%A A274996 _Alois P. Heinz_, Nov 11 2016