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 A178179 #28 Jan 05 2025 19:51:39
%S A178179 0,1,1,2,2,5,3,5,13,7,5,5,17,3,5,5,13,23,41,11,5,19,7,31,19,19,23,61,
%T A178179 103,17,181,43,241,31,7,31,23,61,23,107,191,107,5,101,71,59,11,47,13,
%U A178179 71,131,43,7,181,11,199,23,233,13,269,103,11,383,71,31,97,199,109,5,313,61,379,251,691,1321,73,139,73,19,11,103,19,19,47,17,83,7,107,197,311,41,61,59,23,13,19,11,43,73,127,3,29,53,17,11,3,31
%N A178179 Like A177904, but start with a(1)=0, a(2)=a(3)=1.
%C A178179 After 7 steps, enters a cycle of length 100. The complete cycle, ending at 31, is shown.
%H A178179 Mihai Caragiu, <a href="http://mihai-caragiu-maths.blogspot.com/">Mathematical Trips</a>.
%H A178179 Greg Back and Mihai Caragiu, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Papers1/48-4/Back_Caragiu.pdf">The Greatest Prime Factor and Recurrent Sequences</a>, Fibonacci Quart. 48 (2010), no. 4, 358-362.
%t A178179 a[1] = 0; a[2] = a[3] = 1; a[n_] := a[n] = FactorInteger[a[n - 1] + a[n - 2] + a[n - 3]][[-1, 1]]; Array[a, 107] (* _Robert G. Wilson v_, Nov 17 2014 *)
%t A178179 nxt[{a_,b_,c_}]:={b,c,FactorInteger[a+b+c][[-1,1]]}; NestList[nxt,{0,1,1},110][[All,1]] (* _Harvey P. Dale_, Jul 17 2017 *)
%Y A178179 Cf. A177904.
%K A178179 nonn
%O A178179 1,4
%A A178179 _N. J. A. Sloane_, Dec 19 2010