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 A213312 #7 Sep 01 2012 11:48:11 %S A213312 101,102,105,109,110,114,116,118,120,121,124,126,128,141,142,145,149, %T A213312 150,154,156,158,161,162,165,181,182,185,187,189,190,194,196,198,200, %U A213312 201,204,206,208,209,210,214,216,218,240 %N A213312 Numbers with exactly 5 nonprime substrings (substrings with leading zeros are considered to be nonprime). %C A213312 The sequence is finite. Proof: Each 7-digit number has at least 6 nonprime substrings. Thus, each number with more than 7 digits has >= 6 nonprime substrings, too. Consequently, there is a boundary b<10^6, such that all numbers > b have more than 5 nonprime substrings. %C A213312 The first term is a(1)=101=A213302(5). The last term is a(1330)=831373=A213300(5). %H A213312 Hieronymus Fischer, <a href="/A213312/b213312.txt">Table of n, a(n) for n = 1..1330</a> %e A213312 a(1)=101, since 101 has 5 nonprime substrings (0, 01, 1, 1, 10). %e A213312 a(1330)= 831373, since there are 5 nonprime substrings (1, 8, 831, 8313, 31373). %Y A213312 Cf. A019546, A035232, A039996, A046034, A069489, A085823, A211681, A211682, A211684, A211685. %Y A213312 Cf. A035244, A079307, A213300 - A213321. %K A213312 nonn,fini,base %O A213312 1,1 %A A213312 _Hieronymus Fischer_, Aug 26 2012