%I #13 May 29 2023 11:46:59
%S 1,1,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,
%T 3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,
%U 2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7,2,3,5,2,7,3,2,5,7
%N a(1)=a(2)=1; thereafter a(n) = lpf(a(n-1)+a(n-2)), where lpf = "least prime factor".
%C Cycles with a period of length 9.
%t nxt[{a_,b_}]:={b,FactorInteger[a+b][[1,1]]}; NestList[nxt,{1,1},110][[;;,1]] (* or *) PadRight[ {1,1},110,{5,7,2,3,5,2,7,3,2}] (* _Harvey P. Dale_, May 29 2023 *)
%Y Cf. A000045, A175723, A020639, A178095.
%K nonn
%O 1,3
%A _N. J. A. Sloane_, Dec 16 2010