%I #18 Oct 16 2019 03:15:30
%S 6,8,4,32,49,45,60,125,82,66,150,129,559,417,358,378,314,279,247,183,
%T 1152,1102,2265,1929,1658,1524,1414,5708,8047,6033,8430,8020,7852,
%U 11805,11715,9388,12622,13471,13146,12562,12512,20830,16869,13492,58832
%N Smallest composite that when added to sum of prime factors reaches a prime after n iterations.
%H Donovan Johnson, <a href="/A050710/b050710.txt">Table of n, a(n) for n = 1..200</a>
%e n = 2 gives a(2) = 8 -> 8 = 2*2*2 so 8 + (2+2+2) = 14 and composite (iteration 1); 14 = 2*7 so 14 + (2+7) = 23 and already prime after the second iteration.
%t a[n_]:=Length[NestWhileList[#+Total[Times@@@FactorInteger[#]]&,n,!PrimeQ[#] &]]-1; t={}; Do[i=2; While[a[i]!=n,i++]; AppendTo[t,i], {n,45}]; t (* _Jayanta Basu_, May 25 2013 *)
%Y Cf. A050703, A050704, A050705, A050706, A050707, A050708, A050709.
%Y See also A050767.
%K nonn
%O 1,1
%A _Patrick De Geest_, Aug 15 1999
%E More terms from _Michel ten Voorde_
|