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 A005167 M1957 #32 Nov 17 2023 19:18:02
%S A005167 1,2,9,2193,5782218987645,
%T A005167 223567225753623833253893162919867828939456664850241
%N A005167 a(n+1) = (1 + a(0)^4 + ... + a(n)^4 )/(n+1) (not always integral!).
%C A005167 Terms are integer until n=A097398(3,2)=97.
%C A005167 Guy states that by computing the sequence modulo 97 it is easy to show that a(97) is not integral. - _T. D. Noe_, Sep 17 2007
%C A005167 The next term -- a(6) -- has 201 digits. - _Harvey P. Dale_, Nov 20 2018
%D A005167 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A005167 T. D. Noe, <a href="/A005167/b005167.txt">Table of n, a(n) for n=0..7</a>
%H A005167 R. K. Guy, <a href="http://www.jstor.org/stable/2322249">The strong law of small numbers</a>. Amer. Math. Monthly 95 (1988), no. 8, 697-712.
%H A005167 R. K. Guy, <a href="/A005165/a005165.pdf">The strong law of small numbers</a>. Amer. Math. Monthly 95 (1988), no. 8, 697-712. [Annotated scanned copy]
%H A005167 N. Lygeros & M. Mizony, <a href="http://igd.univ-lyon1.fr/home/mizony/premiers.html">Study of primality of terms of a_k(n)=(1+(sum from 1 to n-1)(a_k(i)^k))/(n-1)</a> [dead link]
%H A005167 Alex Stone, <a href="https://www.quantamagazine.org/the-astonishing-behavior-of-recursive-sequences-20231116/">The Astonishing Behavior of Recursive Sequences</a>, Quanta Magazine, Nov 16 2023, 13 pages.
%t A005167 nxt[{n_,a_,t_}]:={n+1,(1+t)/(n+1),t+((1+t)/(n+1))^4}; NestList[nxt,{0,1,1},5][[All,2]] (* _Harvey P. Dale_, Nov 20 2018 *)
%Y A005167 Cf. A005166, A003504.
%Y A005167 Cf. A108394.
%K A005167 easy,nonn,nice
%O A005167 0,2
%A A005167 _N. J. A. Sloane_