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A049229 Primes p such that p-2 is not squarefree. 2
11, 29, 47, 83, 101, 127, 137, 149, 173, 191, 227, 263, 277, 281, 317, 353, 389, 443, 461, 479, 509, 541, 569, 577, 587, 607, 641, 659, 677, 727, 821, 827, 839, 857, 877, 911, 929, 947, 977, 983, 1019, 1031, 1091, 1109, 1129, 1163, 1181, 1217, 1277, 1289 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence is infinite and its relative density in the sequence of the primes is equal to 1 - 2 * Product_{p prime} (1-1/(p*(p-1)) = 1 - 2 * A005596 = 0.252088... - Amiram Eldar, Feb 27 2021

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Prime[Range[2, 300]], !SquareFreeQ[#-2]&] (* Harvey P. Dale, Nov 14 2012 *)

PROG

(PARI) isok(p) = (p>2) && isprime(p) && !issquarefree(p-2); \\ Michel Marcus, May 14 2018

CROSSREFS

Cf. A005596, A013929, A049231, A049232.

Sequence in context: A167521 A031338 A301621 * A282538 A236485 A039316

Adjacent sequences:  A049226 A049227 A049228 * A049230 A049231 A049232

KEYWORD

nonn

AUTHOR

Labos Elemer

STATUS

approved

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Last modified August 4 21:32 EDT 2021. Contains 346455 sequences. (Running on oeis4.)