This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A065451 #28 Jan 05 2025 19:51:36
%S A065451 0,1,1,1,1,3,1,8,3,8,3,55,3,144,8,21,21,987,8,2584,21,144,55,17711,21,
%T A065451 6765,144,2584,144,317811,21,832040,987,6765,987,46368,144,14930352,
%U A065451 2584,46368,987,102334155,144,267914296,6765,46368,17711,1836311903
%N A065451 a(n) = Fibonacci(phi(n)), a(0) = 0.
%H A065451 Harry J. Smith, <a href="/A065451/b065451.txt">Table of n, a(n) for n = 0..1000</a>
%H A065451 Florian Luca, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/37-3/luca.pdf">Arithmetic Functions of Fibonacci Numbers</a>, The Fibonacci Quarterly, Vol. 37, No. 3 (1999), pp. 265-268.
%H A065451 Joseph L. Pe, <a href="http://numeratus.net/phibonacci/phibonacci.html">The Euler Phibonacci Sequence: A Problem Proposal with Software</a>, 2001.
%F A065451 a(n) = A000045(A000010(n)).
%F A065451 a(n) <= A065449(n), with equality if and only if n = 1, 2 or 3 (Luca, 1999). - _Amiram Eldar_, Jan 12 2022
%e A065451 a(13) = F(phi(13)) = F(12) = 144.
%t A065451 Table[ Fibonacci[ EulerPhi[ n]], {n, 0, 60} ]
%o A065451 (PARI) for(n=1,75,print1(fibonacci(eulerphi(n)),","))
%o A065451 (PARI) { for (n=0, 1000, if (n, a=fibonacci(eulerphi(n)), a=0); write("b065451.txt", n, " ", a) ) } \\ _Harry J. Smith_, Oct 20 2009
%o A065451 (Magma) [0] cat [Fibonacci(EulerPhi(n)): n in [1..50]]; // _G. C. Greubel_, Jan 18 2018
%Y A065451 Cf. A000010, A000045, A065449 (phi(Fibonacci(n))).
%K A065451 nonn
%O A065451 0,6
%A A065451 _Joseph L. Pe_, Nov 18 2001
%E A065451 More terms from several correspondents, Nov 19 2001