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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A172072 Numbers n such that either prime(n)-5/2-+7/2 is prime. 1
1, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 17, 19, 21, 22, 24, 27, 28, 29, 30, 33, 37, 38, 40, 41, 45, 46, 50, 51, 52, 55, 56, 57, 59, 61, 65, 66, 68, 71, 72, 74, 75, 77, 85, 87, 90, 91, 97, 101, 103, 104, 106, 108, 109, 111, 112, 114, 118, 119, 120, 124, 130, 131, 134, 144 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

a(1)=1 because prime(1)-5/2-7/2=2-5/2-7/2=-4(nonprime) and prime(1)-5/2+7/2=2-5/2+7/2=3(prime).

PROG

(PARI) is(n, p=prime(n))=isprime(p-6) || isprime(p+1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A000040, A046117, A172071.

Sequence in context: A161839 A285619 A120190 * A121542 A182306 A023379

Adjacent sequences:  A172069 A172070 A172071 * A172073 A172074 A172075

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Jan 25 2010

EXTENSIONS

Corrected (57 inserted) by R. J. Mathar, May 02 2010

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 22 10:24 EDT 2019. Contains 322330 sequences. (Running on oeis4.)