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 A247947 #16 Nov 20 2014 16:52:22
%S A247947 1027,1037,1043,1047,1057,1059,1067,1073,1079,1203,1205,1207,1243,
%T A247947 1247,1253,1257,1263,1267,1273,1285,1293,1329,1345,1347,1349,1357,
%U A247947 1369,1379,1385,1387,1389,1397,1403,1405,1437,1457,1465,1469,1473,1497,1507,1509,1527,1529
%N A247947 Four-digit odd semiprimes with all digits distinct.
%C A247947 There are exactly 863 four-digit odd semiprimes with all distinct digits. The last few terms of the sequence are: 9563, 9571, 9573, 9607, 9617, 9627, 9637, 9641, 9647, 9651, 9671, 9673, 9683, 9687, 9701, 9703, 9713, 9731, 9745, 9753, 9761, 9763, 9813, 9827, 9841, 9847, 9853, 9863, 9865.
%C A247947 See the link with the b-file for all 863 entries.
%H A247947 K. D. Bajpai, <a href="/A247947/b247947.txt">Table of n, a(n) for n = 1..863</a>
%e A247947 a(1) = 1027 = 13 * 79 is the smallest four-digit odd semiprime with all digits distinct.
%e A247947 a(863) = 9865 = 5 * 1973 is the largest four-digit odd semiprime with all digits distinct.
%t A247947 c = 0; Do[If[Length[Union[IntegerDigits[n]]] == 4 && PrimeOmega[n] == 2, c++; Print[c, " ", n]], {n, 1001, 9999, 2}]
%Y A247947 Cf. A001358, A046315, A074673, A235690.
%K A247947 nonn,base,fini,full
%O A247947 1,1
%A A247947 _K. D. Bajpai_, Sep 27 2014