A049229 Primes p such that p-2 is not squarefree.

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

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