This site is supported by donations to The OEIS Foundation.

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 4500 articles have referenced us, often saying "we would not have discovered this result without the OEIS".

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A023201 Numbers n such that n and n + 6 are both prime. 84
 5, 7, 11, 13, 17, 23, 31, 37, 41, 47, 53, 61, 67, 73, 83, 97, 101, 103, 107, 131, 151, 157, 167, 173, 191, 193, 223, 227, 233, 251, 257, 263, 271, 277, 307, 311, 331, 347, 353, 367, 373, 383, 433, 443, 457, 461, 503, 541, 557, 563, 571, 587, 593, 601, 607, 613, 641, 647 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also known as sexy primes. - John W. Nicholson, Mar 23 2015 LINKS T. D. Noe, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Sexy Primes. Eric Weisstein's World of Mathematics, Twin Primes MAPLE A023201 := proc(n)     option remember;     if n = 1 then         5;     else         for a from procname(n-1)+2 by 2 do             if isprime(a) and isprime(a+6) then                 return a;             end if;         end do:     end if; end proc: # R. J. Mathar, May 28 2013 MATHEMATICA Select[Range[10^2], PrimeQ[ # ]&&PrimeQ[ #+6] &] (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *) PROG (MAGMA) [n: n in [0..40000] | IsPrime(n) and IsPrime(n+6)] // Vincenzo Librandi, Aug 04 2010 (Haskell) a023201 n = a023201_list !! (n-1) a023201_list = filter ((== 1) . a010051 . (+ 6)) a000040_list -- Reinhard Zumkeller, Feb 25 2013 (PARI) is(n)=isprime(n+6)&&isprime(n) \\ Charles R Greathouse IV, Mar 20 2013 CROSSREFS A031924 and A007529 together give A023201. Cf. A046117, A098428, A000040, A010051, A006489 (subsequence). Sequence in context: A040146 A243593 A015914 * A106059 A102386 A038958 Adjacent sequences:  A023198 A023199 A023200 * A023202 A023203 A023204 KEYWORD nonn,easy AUTHOR STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .