

A049282


Primes p such that both p2 and p+2 are squarefree.


10



3, 5, 13, 17, 19, 31, 37, 41, 53, 59, 67, 71, 89, 103, 107, 109, 113, 131, 139, 157, 163, 179, 181, 193, 197, 199, 211, 229, 233, 239, 251, 257, 269, 271, 283, 293, 307, 311, 337, 347, 379, 383, 397, 401, 409, 419, 431, 433, 449, 463, 467, 487, 491, 499, 503
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OFFSET

1,1


LINKS

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


FORMULA

Intersection of A049231 and A049233.


EXAMPLE

37 is here because neither 37+2 nor 372 is divisible by squares.


MAPLE

with(numtheory): A049282:=n>`if`(isprime(n) and issqrfree(n2) and issqrfree(n+2), n, NULL): seq(A049282(n), n=1..10^3); # Wesley Ivan Hurt, Jun 25 2016


MATHEMATICA

lst={}; Do[p=Prime[n]; If[SquareFreeQ[p2]&&SquareFreeQ[p+2], AppendTo[lst, p]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 20 2008 *)


PROG

(PARI) lista(nn) = forprime(p=2, nn, if (issquarefree(p2) && issquarefree(p+2), print1(p, ", "))); \\ Michel Marcus, Jun 22 2016


CROSSREFS

Cf. A049231, A049233.
Sequence in context: A045411 A184796 A180944 * A003625 A105900 A260191
Adjacent sequences: A049279 A049280 A049281 * A049283 A049284 A049285


KEYWORD

nonn


AUTHOR

Labos Elemer


STATUS

approved



