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 A048849 #15 Feb 22 2024 20:23:43
%S A048849 3,4,7,9,17,15,29,25,35,35,59,43,77,55,65,71,111,73,127,89,109,107,
%T A048849 161,107,167,137,163,143,215,131,239,183,207,191,237,187,307,223,255,
%U A048849 225,351,217,371,263,285,277,409,275,407,299,363,327,479,311,429,351,419
%N A048849 a(n) = prime(phi(n)) + phi(prime(n)).
%C A048849 I made this up to demonstrate how easy it is to construct dull but unguessable sequences with short descriptions.
%H A048849 G. C. Greubel, <a href="/A048849/b048849.txt">Table of n, a(n) for n = 1..10000</a>
%p A048849 with(numtheory); [ seq(ithprime(phi(i))+phi(ithprime(i)),i=1..80) ];
%t A048849 Table[Prime[EulerPhi[n]] + EulerPhi[Prime[n]], {n,100}] (* _G. C. Greubel_, Feb 22 2024 *)
%o A048849 (Magma) [NthPrime(EulerPhi(n)) + EulerPhi(NthPrime(n)) : n in [1..100]]; // _G. C. Greubel_, Feb 22 2024
%o A048849 (SageMath) [nth_prime(euler_phi(n)) + euler_phi(nth_prime(n)) for n in range(1,101)] # _G. C. Greubel_, Feb 22 2024
%Y A048849 Cf. A000010, A000040, A048848.
%K A048849 nonn,easy
%O A048849 1,1
%A A048849 _N. J. A. Sloane_
%E A048849 Offset corrected by _G. C. Greubel_, Feb 22 2024