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%I #14 Sep 16 2015 13:39:48
%S 1,3,5,7,3,19,67,179,31,311,59,709,419,5867,557,2971,61,157,373,829,
%T 1741,38303,2381,1039,191,4967,13411,375509,418837,966547,14981479,
%U 16127,16631,149,163,5869,15511,829,137,29,17,13,7,103,61,401,31,1489
%N a(1)=1; for n>=2, a(n) = the largest prime dividing n*a(n-1) + 1.
%H Harvey P. Dale, <a href="/A134487/b134487.txt">Table of n, a(n) for n = 1..1000</a>
%e a(9)=31 because 9*a(8) + 1 = 9*179 + 1 = 1612 = 2*2*13*31.
%p with(numtheory): a:=proc(n) local f, L: if n = 1 then 1 else f:=factorset(1+n*a(n-1)): L:=convert(f,list): L[nops(L)] end if end proc: seq(a(n),n=1..35); # _Emeric Deutsch_, Nov 12 2007
%t a = {1}; Do[AppendTo[a, FactorInteger[(Length[a] + 1)*a[[ -1]] + 1][[ -1, 1]]], {70}]; a (* _Stefan Steinerberger_, Oct 30 2007 *)
%t nxt[{a_,n_}]:={FactorInteger[a(n+1)+1][[-1,1]],n+1}; Transpose[ NestList[ nxt,{1,1},50]][[1]] (* _Harvey P. Dale_, Jun 02 2014 *)
%Y Cf. A134486.
%K nonn
%O 1,2
%A _Leroy Quet_, Oct 28 2007
%E More terms from _Stefan Steinerberger_, Oct 30 2007
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