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 A118689 #7 Dec 27 2013 15:21:04
%S A118689 4,6,9,14,22,25,33,35,55,57,77,91,119,122,123,133,141,155,161,177,213,
%T A118689 215,217,221,321,371,411,515,517,551,611,713,717,721,731,771,1114,
%U A118689 1119,1133,1135,1137,1141,1157,1177,1191,1271,1313,1315,1317,1351,1371,1411
%N A118689 Semiprimes for which the product of the digits is also a semiprime.
%H A118689 Harvey P. Dale, <a href="/A118689/b118689.txt">Table of n, a(n) for n = 1..300</a>
%e A118689 77 is in the sequence because (1 )it is a semiprime and (2) the product of its digits 7*7=49 is also a semiprime.
%t A118689 Select[Range[2000],PrimeOmega[#]==PrimeOmega[Times@@IntegerDigits[#]] == 2&] (* _Harvey P. Dale_, Dec 27 2013 *)
%o A118689 (PARI) A007954(n)= { local(resul) ; if(n==0, return(0) ; ) ; resul= 1 ; while(n>0, resul *= n%10 ; n = (n-n%10)/10 ; ) ; return(resul) ; } { for(n=4,2000, if( bigomega(n)==2, if(A007954(n) != 0 && bigomega(A007954(n)) == 2, print1(n,","); ) ; ) ; ) ; } - _R. J. Mathar_, Aug 21 2006
%Y A118689 Cf. A001358.
%K A118689 base,nonn
%O A118689 1,1
%A A118689 Luc Stevens (lms022(AT)yahoo.com), May 20 2006