A006489 Numbers k such that k-6, k, and k+6 are primes. (Formerly M4770)

11, 13, 17, 23, 37, 47, 53, 67, 73, 103, 107, 157, 173, 233, 257, 263, 277, 353, 373, 563, 593, 607, 613, 647, 653, 733, 947, 977, 1097, 1103, 1123, 1187, 1223, 1283, 1297, 1367, 1433, 1453, 1487, 1493, 1607, 1613, 1663, 1747, 1753, 1783, 1867, 1873

Offset

1,1

Comments

A006562 without the first term 5 is a subsequence. - Zak Seidov, Apr 19 2021

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

Joseph Hirsch, Prime Triplets, Mathematics Teacher, 62 (1969), 467ff (see p. 471).

D. S. Kluk and N. J. A. Sloane, Correspondence, 1979

Mathematica

Select[Prime[Range[300]], And@@PrimeQ[#+{6, -6}]&] (* Harvey P. Dale, May 21 2012 *)

Prog

(Haskell)
a006489 n = a006489_list !! (n-1)
a006489_list = filter
   ((== 1) . a010051 . (subtract 6)) $ dropWhile (<= 6) a023201_list
-- Reinhard Zumkeller, Feb 25 2013
(PARI) is(n)=isprime(n-6) && isprime(n) && isprime(n+6) \\ Charles R Greathouse IV, Feb 07 2017

Crossrefs

Subsequence of A023201.

Cf. A006562.

Sequence in context: A048058 A048059 A106076 * A032621 A289701 A250402

Adjacent sequences: A006486 A006487 A006488 * A006490 A006491 A006492

Keyword

nonn,nice,easy

Author

N. J. A. Sloane

Extensions

More terms from James A. Sellers, Dec 24 1999

Status

approved