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 A023189 #19 Aug 25 2025 09:22:21 %S A023189 1,1,1,3,4,4,14,13,16,48,55,50,173,148,147,665,580,559,1920,1447,1975, %T A023189 6240,4228,5689,15764,17562,14332,46207,39071,35317,172311,134752, %U A023189 110758,381384,299971,479935,1154568,733900,1027967,2581763,2636545,2333308,8369027,5516720,6043194 %N A023189 Conjecturally, number of infinitely recurring prime patterns of width 2n-1. %C A023189 Of the patterns counted by A023192, the number of those that start and end with a prime. - _Sean A. Irvine_, May 27 2019 %H A023189 Pontus von Brömssen, <a href="/A023189/b023189.txt">Table of n, a(n) for n = 1..60</a> %e A023189 From _Jon E. Schoenfield_, May 17 2024: (Start) %e A023189 The table below lists every (conjecturally) infinitely recurring prime pattern of width 2n-1 for n = 1..7. Each p represents a prime; each c represents a composite. %e A023189 . %e A023189 n 2n-1 a(n) prime patterns %e A023189 - ---- ---- -------------------------------------------------- %e A023189 1 1 1 p %e A023189 2 3 1 pcp %e A023189 3 5 1 pcccp %e A023189 4 7 3 pcccccp, pcpcccp, pcccpcp %e A023189 5 9 4 pcccccccp, pcpcccccp, pcccccpcp, pcpcccpcp %e A023189 6 11 4 pcccccccccp, pcccpcccccp, pcccccpcccp, pcccpcpcccp %e A023189 7 13 14 pcccccccccccp, pcpcccccccccp, pcccpcccccccp, %e A023189 pcccccpcccccp, pcccccccpcccp, pcccccccccpcp, %e A023189 pcpcccpcccccp, pcpcccccpcccp, pcccpcpcccccp, %e A023189 pcccpcccccpcp, pcccccpcpcccp, pcccccpcccpcp, %e A023189 pcpcccpcpcccp, pcccpcpcccpcp %e A023189 (End) %Y A023189 Cf. A023190, A023191, A023192. %K A023189 nonn,changed %O A023189 1,4 %A A023189 _David W. Wilson_ %E A023189 Name edited by _Jon E. Schoenfield_, May 17 2024 %E A023189 a(43)-a(45) from _Pontus von Brömssen_, Aug 25 2025