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%I #12 Oct 17 2019 12:49:57
%S 36,50,70,110,130,170,190,230,256,290,310,324,370,384,410,430,470,500,
%T 530,540,590,610,670,700,710,730,735,756,784,790,830,890,970,1010,
%U 1030,1070,1090,1100,1130,1155,1188,1270,1300,1310,1352,1365,1370,1390,1490
%N Composite numbers whose decimal expansion starts with their largest prime divisor.
%H Harvey P. Dale, <a href="/A050691/b050691.txt">Table of n, a(n) for n = 1..1000</a>
%e 1188 = {11}88 = 2*2*3*3*3*{11}.
%t d[n_]:=IntegerDigits[n]; aQ[n_]:=!PrimeQ[n]&&Take[d[n],Length[y=d[Max@@First/@FactorInteger[n]]]]==y; Select[Range[2,1500],aQ[#]&] (* _Jayanta Basu_, May 30 2013 *)
%t lpfQ[n_]:=Module[{c=IntegerDigits[FactorInteger[n][[-1,1]]]},CompositeQ[ n] && Take[IntegerDigits[n],Length[c]]==c]; Select[Range[1500],lpfQ] (* _Harvey P. Dale_, Dec 20 2014 *)
%Y Cf. A050692, A050693.
%K nonn,base
%O 1,1
%A _Patrick De Geest_, Aug 15 1999
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