This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A094298 #18 Jul 07 2024 21:03:09 %S A094298 4,6,14,15,26,35,38,49,51,62,65,74,85,86,91,94,111,121,122,129,134, %T A094298 158,159,169,183,185,187,201,206,209,215,219,221,237,247,254,287,301, %U A094298 302,303,305,319,321,326,329,365,371,377,386,403,411,417,427,446,447,458 %N A094298 Numbers m such that m and its 10's complement are both semiprimes, i.e., m and 10^k - m, where k is the number of digits of m, are semiprime. %H A094298 Robert Israel, <a href="/A094298/b094298.txt">Table of n, a(n) for n = 1..10000</a> %e A094298 201 is a term because both 201 and 1000 - 201 = 799 are semiprimes. %p A094298 tc:= n -> 10^(1+ilog10(n))-n: %p A094298 filter:= proc(n) numtheory:-bigomega(n)=2 and numtheory:-bigomega(tc(n))=2 end proc: %p A094298 select(filter, [$1..1000]); # _Robert Israel_, Jul 02 2024 %t A094298 Select[Range[500],PrimeOmega[#]==PrimeOmega[10^IntegerLength[#]-#]==2&] (* _Harvey P. Dale_, Jan 17 2013 *) %Y A094298 Cf. A001358, A089186. %K A094298 easy,nonn,base %O A094298 1,1 %A A094298 _Jason Earls_, Jun 02 2004