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A106553
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Semiprime + (largest integer obtained by concatenating its two divisors).
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1
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26, 38, 42, 62, 86, 68, 94, 233, 80, 239, 344, 251, 110, 257, 352, 278, 126, 368, 566, 376, 350, 374, 578, 392, 446, 788, 494, 602, 518, 416, 804, 424, 566, 614, 638, 484, 638, 710, 836, 1232, 734, 536, 562, 852, 806, 614, 854, 1454, 674, 878, 686, 950, 692
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OFFSET
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1,1
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LINKS
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EXAMPLE
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First semiprime is 4; 4 is 2*2; 26=4+22.
Second semiprime is 6; 6 is 2*3 (23) or 3*2 (32); 38=6+32.
...
Eighth semiprime is 22; 22 is 2*11 (211) or 11*2 (112); 233=22+211.
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MATHEMATICA
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licd[n_]:=Module[{fi=Flatten[Table[#[[1]], #[[2]]]&/@FactorInteger[n], 1]}, Max[fi[[1]]*10^IntegerLength[ fi[[2]]]+fi[[2]], fi[[2]]*10^IntegerLength[ fi[[1]]]+fi[[1]]]+n]; licd/@(Select[Range[200], PrimeOmega[#]==2&]) (* Harvey P. Dale, Jul 22 2019 *)
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CROSSREFS
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KEYWORD
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base,easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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