login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A268612 Primes p such that p + 2 k, for k = 1..7 are squarefree. 1
29, 83, 101, 191, 227, 389, 443, 479, 587, 641, 659, 677, 983, 1091, 1109, 1289, 1307, 1451, 1487, 2027, 2081, 2153, 2243, 2333, 2351, 2441, 2459, 2477, 2549, 2657, 2729, 2837, 2909, 2927, 2999, 3089, 3251, 3359, 3449, 3557, 3593, 4007 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Eight consecutive odd numbers starting with p are squarefree.

This is the longest set as p+16 in all cases are divisible by 9.

All terms are congruent to 11 mod 18.

LINKS

Zak Seidov, Table of n, a(n) for n = 1..1592

PROG

(MAGMA) [p: p in PrimesUpTo(4500) | forall{k: k in [1..7] | IsSquarefree(p+2*k)}]; // Vincenzo Librandi, Feb 09 2016

CROSSREFS

Cf. A049097, A049233.

Sequence in context: A141930 A153680 A097722 * A156784 A142592 A255187

Adjacent sequences:  A268609 A268610 A268611 * A268613 A268614 A268615

KEYWORD

nonn

AUTHOR

Zak Seidov, Feb 08 2016

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.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 19 02:06 EST 2018. Contains 299330 sequences. (Running on oeis4.)