This site is supported by donations to The OEIS Foundation.

The October issue of the Notices of the Amer. Math. Soc. has an article about the OEIS.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A215918 Numbers n such that 6*n + {1, 5, 7}  are all primes. 1
 1, 2, 6, 11, 16, 17, 32, 37, 46, 51, 76, 102, 137, 142, 146, 181, 216, 237, 241, 247, 277, 282, 297, 311, 312, 332, 347, 356, 396, 447, 451, 466, 527, 542, 576, 577, 641, 692, 752, 797, 871, 902, 906, 941, 942, 956, 1091, 1137, 1201, 1292, 1312, 1381, 1437 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Subsequence of A056956. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 FORMULA a(n) = (A022005(n)-1)/6. MATHEMATICA Select[Range[1437], Union[PrimeQ[6 # + {1, 5, 7}]] == {True} &] (* T. D. Noe, Aug 27 2012 *) PROG (PARI) for(n=1, 2000, if(isprime(6*n+1)&&isprime(6*n+5)&&isprime(6*n+7), print(n", "))) (MAGMA) [n: n in [1..1000] | forall{6*n+r: r in [1, 5, 7] | IsPrime(6*n+r)}]; // Bruno Berselli, Aug 27 2012 CROSSREFS Cf. A022005, A056956. Sequence in context: A190889 A020966 A193910 * A078476 A217687 A212459 Adjacent sequences:  A215915 A215916 A215917 * A215919 A215920 A215921 KEYWORD nonn,easy AUTHOR Zak Seidov, Aug 27 2012 STATUS approved

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

Last modified September 25 22:57 EDT 2018. Contains 315425 sequences. (Running on oeis4.)