cp's OEIS Frontend

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.

A023189 Conjecturally, number of infinitely recurring prime patterns of width 2n-1.

Original entry on oeis.org

1, 1, 1, 3, 4, 4, 14, 13, 16, 48, 55, 50, 173, 148, 147, 665, 580, 559, 1920, 1447, 1975, 6240, 4228, 5689, 15764, 17562, 14332, 46207, 39071, 35317, 172311, 134752, 110758, 381384, 299971, 479935, 1154568, 733900, 1027967, 2581763, 2636545, 2333308, 8369027, 5516720, 6043194
Offset: 1

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Comments

Of the patterns counted by A023192, the number of those that start and end with a prime. - Sean A. Irvine, May 27 2019

Examples

			From _Jon E. Schoenfield_, May 17 2024: (Start)
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.
.
  n  2n-1  a(n)  prime patterns
  -  ----  ----  --------------------------------------------------
  1     1     1  p
  2     3     1  pcp
  3     5     1  pcccp
  4     7     3  pcccccp, pcpcccp, pcccpcp
  5     9     4  pcccccccp, pcpcccccp, pcccccpcp, pcpcccpcp
  6    11     4  pcccccccccp, pcccpcccccp, pcccccpcccp, pcccpcpcccp
  7    13    14  pcccccccccccp, pcpcccccccccp, pcccpcccccccp,
                 pcccccpcccccp, pcccccccpcccp, pcccccccccpcp,
                 pcpcccpcccccp, pcpcccccpcccp, pcccpcpcccccp,
                 pcccpcccccpcp, pcccccpcpcccp, pcccccpcccpcp,
                 pcpcccpcpcccp, pcccpcpcccpcp
(End)
		

Crossrefs

Extensions

Name edited by Jon E. Schoenfield, May 17 2024
a(43)-a(45) from Pontus von Brömssen, Aug 25 2025