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 A214893 #14 Oct 20 2022 23:59:39
%S A214893 18,5,23,14,37,17,27,22,7,29,18,47,13,30,43,73,58,131,63,97,80,59,139,
%T A214893 99,119,109,114,223,337,280,617,299,458,757,405,581,493,537,515,526,
%U A214893 347,291,319,305,312,617,929
%N A214893 Conway's subprime Fibonacci sequence starting with (18, 5).
%C A214893 Similar to the Fibonacci recursion starting with (18, 5), but each new nonprime term is divided by its least prime factor. Sequence enters a loop of length 56 after 26 terms on reaching (119, 109).
%H A214893 Wouter Meeussen, <a href="/A214893/b214893.txt">Table of n, a(n) for n = 1..82</a>
%H A214893 Richard K. Guy, Tanya Khovanova and Julian Salazar, <a href="http://arxiv.org/abs/1207.5099">Conway's subprime Fibonacci sequences</a>, arXiv:1207.5099v1 [math.NT]
%t A214893 see A214674
%t A214893 nxt[{a_,b_}]:=Module[{c=a+b},{b,If[PrimeQ[c],c,c/FactorInteger[c][[1,1]]]}]; Transpose[NestList[nxt,{18,5},82]][[1]] (* _Harvey P. Dale_, Oct 19 2012 *)
%Y A214893 Cf. A000045, A020639, A175723, A214551, A014682, A214674, A214892-A214898.
%K A214893 nonn
%O A214893 1,1
%A A214893 _Wouter Meeussen_, Jul 29 2012