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 A197219 #22 Jan 23 2025 16:50:41
%S A197219 2,1,1,3,3,7,3,18,7,18,7,123,7,322,18,47,47,2207,18,5778,47,322,123,
%T A197219 39603,47,15127,322,5778,322,710647,47,1860498,2207,15127,2207,103682,
%U A197219 322,33385282,5778,103682,2207,228826127,322,599074578,15127,103682,39603
%N A197219 a(0) = 2, a(n) = Lucas(phi(n)) for n > 0.
%H A197219 Vincenzo Librandi, <a href="/A197219/b197219.txt">Table of n, a(n) for n = 0..200</a>
%F A197219 a(n) = A000032(A000010(n)) for n > 0.
%t A197219 Table[LucasL[EulerPhi[n]], {n, 0, 50}]
%o A197219 (Magma) [2] cat [Lucas(EulerPhi(n)): n in [1..60]]; // _Vincenzo Librandi_, Oct 13 2011
%o A197219 (PARI) a(n) = if(n==0, 2, fibonacci(eulerphi(n)+1) + fibonacci(eulerphi(n)-1)) \\ _G. C. Greubel_, Dec 22 2017
%Y A197219 Cf. A000010, A000032, A065449, A065451, A197218 (phi(Lucas(n))).
%K A197219 nonn
%O A197219 0,1
%A A197219 _T. D. Noe_, Oct 12 2011