A075750 210*n -/+ 11 are primes.

2, 3, 5, 7, 9, 10, 13, 17, 26, 29, 34, 45, 48, 54, 57, 59, 60, 61, 63, 75, 82, 89, 108, 112, 113, 123, 133, 136, 139, 140, 146, 147, 148, 150, 151, 153, 156, 166, 167, 172, 173, 174, 175, 177, 184, 185, 195, 208, 210, 215, 227, 245, 250, 265, 266, 269, 278, 279

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

n=2: 210*2-11=409 and 210*2+11=431 are primes.

Mathematica

Select[Range[1, 300], PrimeQ[210 # - 11]&&PrimeQ[210 # + 11] &] (* Vincenzo Librandi, Oct 05 2013 *)

Prog

(PARI) isok(n) = isprime(210*n+11) && isprime(210*n-11); \\ Michel Marcus, Oct 03 2013
(Magma) [n: n in [1..350] | IsPrime(210*n-11) and IsPrime(210*n+11)]; // Vincenzo Librandi, Oct 05 2013

Crossrefs

Sequence in context: A103635 A133677 A362403 * A331232 A219050 A036049

Adjacent sequences: A075747 A075748 A075749 * A075751 A075752 A075753

Keyword

easy,nonn

Author

Zak Seidov, Oct 08 2002

Status

approved