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 A288354 #9 Jun 11 2017 12:39:56 %S A288354 1251,1261,1271,1272,1273,1281,1282,1283,1291,1292,1294,1295,1316, %T A288354 1317,1318,1319,1354,1356,1361,1365,1367,1371,1372,1376,1378,1381, %U A288354 1383,1387,1389,1391,1392,1394,1398,1417,1418,1419,1424,1464,1465,1467,1468,1471,1475,1476,1478,1479,1481,1486,1487,1489,1491,1492,1497,1498 %N A288354 Strings of 4 digits from 1...9, such that no formula using the single digits in the given order exists that evaluates to 0. %C A288354 For definitions and comments see A288350. The b-file provides all A288351(4)=1500 sequence terms. %H A288354 Hugo Pfoertner, <a href="/A288354/b288354.txt">Table of n, a(n) for n = 1..1500</a> %Y A288354 Cf. A288350, A288351, A288353, A288355, A288356. %K A288354 nonn,base,fini,full %O A288354 1,1 %A A288354 _Hugo Pfoertner_, Jun 08 2017