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 A235692 #7 Apr 29 2014 22:49:29 %S A235692 1027,1037,1042,1043,1046,1047,1057,1059,1067,1073,1079,1082,1094, %T A235692 1203,1205,1207,1234,1238,1243,1247,1253,1257,1263,1267,1273,1285, %U A235692 1286,1293,1294,1306,1329,1345,1346,1347,1349,1354,1357,1369,1379,1382,1385,1387,1389 %N A235692 Semiprimes which have one or more occurrences of exactly four different digits. %C A235692 The first term having a repeated digit is 10027. %o A235692 (PARI) %o A235692 list(lim)=my(v=List(), t); forprime(p=2, sqrt(lim), t=p; forprime(q=p, lim\t, listput(v, t*q))); vecsort(Vec(v)) \\ From A001358 %o A235692 b=list(15000); s=[]; for(n=1, #b, if(#vecsort(eval(Vec(Str(b[n]))),,8)==4, s=concat(s, b[n]))); s %Y A235692 Cf. A235690, A235691, A235693-A235696. %Y A235692 Cf. A235154-A235161. %K A235692 nonn,base %O A235692 1,1 %A A235692 _Colin Barker_, Jan 14 2014