%I #8 Aug 06 2018 13:25:20
%S 1,2,3,3,3,3,5,5,5,5,7,7,7,7,7,7,11,11,11,11,11,11,13,13,13,13,13,13,
%T 17,17,17,17,17,17,19,19,19,19,19,19,23,23,23,23,23,23,23,23,23,23,29,
%U 29,29,29,29,29,29,29,31,31,31,31,31,31,31,31,37,37,37,37,37,37,37,37,37,37,41
%N a(1) = 1, a(2) = 2, then a(n) = largest prime factor of the partial sum up to a(n-1).
%H Harvey P. Dale, <a href="/A155047/b155047.txt">Table of n, a(n) for n = 1..1000</a>
%p A006530 := proc(n) max(op(numtheory[factorset](n))) ; end:
%p A155047 := proc(n) option remember; if n <=2 then n; else A006530( add(procname(i),i=1..n-1)) ; fi; end:
%p seq(A155047(n),n=1..120) ; # _R. J. Mathar_, Oct 23 2009
%t nxt[{t_,a_}]:=Module[{lpf=FactorInteger[t][[-1,1]]},{t+lpf,lpf}]; Join[ {1},NestList[ nxt,{3,2},80][[All,2]]] (* _Harvey P. Dale_, Aug 06 2018 *)
%K easy,nonn
%O 1,2
%A _Giovanni Teofilatto_, Jan 19 2009
%E Extended by _R. J. Mathar_, Oct 23 2009