A086698 Two-sided semiprimes: deleting any number of digits at left or at right, but not both, leaves a semiprime.
4, 6, 9, 46, 49, 69, 94, 469, 626, 694, 914, 934, 939, 949, 4694, 4934, 4939, 9134, 9346, 9586, 62386, 62614, 91346, 959939, 6998339, 91439939
Offset: 1
Examples
a(18)=9134 is a term because 9134, 913,134,34,91,4,9 all are semiprimes.
Programs
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Mathematica
aspQ[n_]:=Module[{idn=IntegerDigits[n]},AllTrue[Union[FromDigits/@Join[NestList[Rest[#]&,idn,Length[idn]-1],NestList[Most[#]&,idn,Length[idn]-1]]],PrimeOmega[#]==2&]]; Select[Range[10^6],aspQ] (* The program generates the first 24 terms of the sequence. *) (* Harvey P. Dale, Sep 04 2025 *)