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 A211684 #15 Jun 28 2018 07:16:34 %S A211684 1131,1137,1139,1271,1277,1311,1313,1317,1373,1379,1397,1491,1499, %T A211684 1571,1577,1631,1673,1677,1733,1739,1797,1811,1911,1919,1937,1971, %U A211684 1977,1991,1997,2113,2233,2239,2271,2277,2293,2331,2337,2397,2419,2571 %N A211684 Numbers > 1000 such that all the substrings of length = 3 are primes (substrings with leading '0' are considered to be nonprime). %C A211684 Only numbers > 1000 are considered, since all 3-digit primes are trivial members. See A069489 for the sequence with prime terms > 1000. %C A211684 The sequence is infinite (for example, consider the continued concatenation of '19' or of '337': 1919, 19191, 191919, ..., 3373, 33733, 337337, ... are members). %C A211684 Infinitely many terms are palindromic. %C A211684 A 10-automatic sequence realized by a linear recurrence relation. - _Charles R Greathouse IV_, Jan 04 2013 %H A211684 Hieronymus Fischer, <a href="/A211684/b211684.txt">Table of n, a(n) for n = 1..3000</a> %H A211684 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>. %e A211684 a(1) = 1131, since all substrings of length = 3 (113 and 131) are primes. %e A211684 a(33) = 2271, since all substrings of length = 3 (227, 271) are primes. %Y A211684 Cf. A019546, A035232, A039996, A046034, A069489, A085823, A211681, A211682. %K A211684 nonn,base,easy %O A211684 1,1 %A A211684 _Hieronymus Fischer_, Jun 08 2012