A155141 Primes p such that both p-+4 are squarefree.

2, 3, 7, 11, 17, 19, 37, 43, 47, 61, 73, 83, 89, 97, 101, 107, 109, 127, 137, 163, 181, 191, 197, 199, 223, 227, 233, 251, 263, 269, 277, 281, 307, 313, 317, 331, 349, 353, 389, 397, 431, 433, 439, 443, 449, 457, 461, 467, 487, 523, 541, 547, 557, 569, 577, 587

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jan 21 2009

Keywords

• nonn

Links

• John Cerkan, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A153213, A049282, A155139, A155140, A155142.

Programs

Mathematica

<Harvey P. Dale, Jun 15 2016 *)

PARI

lista(nn) = forprime(p=2, nn, if (issquarefree(p-4) && issquarefree(p+4), print1(p, ", "))); \\ Michel Marcus, Jul 06 2016