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 A066792 #31 Dec 09 2024 05:28:03
%S A066792 1,2,8,16,64,48,216,160,288,320,1000,480,1344,768,1568,1792,4096,1344,
%T A066792 4320,2880,4800,3840,8448,3328,11520,7488,12168,6912,17472,6720,24960,
%U A066792 13824,16000,13824,25344,14688,46656,19584,26112,24320,64000,19488
%N A066792 a(n) = phi(n^3 + n^2 + n + 1).
%H A066792 Harry J. Smith, <a href="/A066792/b066792.txt">Table of n, a(n) for n = 0..1000</a>
%F A066792 a(n) = A000010(A053698(n)). - _Michel Marcus_, Sep 06 2022
%F A066792 Sum_{k=1..n} a(k) = c * n^4 + O((n*log(n))^3), where c = (3/16) * Product_{primes p == 1 (mod 4)} (1 - 3/p^2) * Product_{primes p == 3 (mod 4)} (1 - 1/p^2) = 0.13549316168... . - _Amiram Eldar_, Dec 09 2024
%t A066792 Prepend[EulerPhi[Total[#^Range[0,3]]]&/@Range[45],1] (* _Harvey P. Dale_, Feb 19 2011 *)
%o A066792 (PARI) a(n) = eulerphi(n^3 + n^2 + n + 1); \\ _Harry J. Smith_, Mar 27 2010
%Y A066792 Cf. A000010 (phi), A053698, A243379.
%K A066792 nonn,easy
%O A066792 0,2
%A A066792 _Benoit Cloitre_, Jan 18 2002