OFFSET
1,1
EXAMPLE
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.
MATHEMATICA
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 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, May 09 2005
EXTENSIONS
Corrected and extended by Harvey P. Dale, Jul 22 2019
STATUS
approved