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 A213315 #7 Sep 01 2012 11:48:35 %S A213315 1011,1012,1015,1021,1022,1025,1027,1029,1030,1034,1036,1038,1043, %T A213315 1047,1051,1052,1055,1057,1059,1061,1063,1067,1070,1074,1076,1078, %U A213315 1083,1087,1091,1092,1095,1101,1102,1105,1110,1114 %N A213315 Numbers with exactly 8 nonprime substrings (substrings with leading zeros are considered to be nonprime). %C A213315 The sequence is finite. Proof: Each 8-digit number has at least 10 nonprime substrings. Thus, each number with more than 8 digits has >= 10 nonprime substrings, too. Consequently, there is a boundary b<10^7, such that all numbers > b have more than 8 nonprime substrings. %C A213315 The first term is a(1)=1011=A213302(8). The last term is a(7483)=8313733=A213300(8). %H A213315 Hieronymus Fischer, <a href="/A213315/b213315.txt">Table of n, a(n) for n = 1..7483</a> %e A213315 a(1)=1011, since 1011 has 8 nonprime substrings (0, 1, 1, 1, 01, 10, 011, 1011). %e A213315 a(7483)= 8313733 since there are 8 nonprime substrings (1, 8, 33, 831, 8313, 13733, 31373, 313733). %Y A213315 Cf. A019546, A035232, A039996, A046034, A069489, A085823, A211681, A211682, A211684, A211685. %Y A213315 Cf. A035244, A079307, A213300 - A213321. %K A213315 nonn,fini,base %O A213315 1,1 %A A213315 _Hieronymus Fischer_, Aug 26 2012