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 A049282 Primes p such that both p-2 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 (list; graph; refs; listen; history; text; internal format)
 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 37-2 is divisible by squares. MAPLE with(numtheory): A049282:=n->`if`(isprime(n) and issqrfree(n-2) 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[p-2]&&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(p-2) && 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

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Last modified December 8 14:49 EST 2023. Contains 367680 sequences. (Running on oeis4.)