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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A141894 Primes congruent to 13 mod 21. 1
13, 97, 139, 181, 223, 307, 349, 433, 601, 643, 727, 769, 811, 853, 937, 1021, 1063, 1231, 1399, 1483, 1567, 1609, 1693, 1777, 1861, 1987, 2029, 2113, 2239, 2281, 2617, 2659, 2953, 3037, 3079, 3121, 3163, 3331, 3373, 3457, 3499, 3541, 3583, 3709, 3793, 3877 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

a(n) ~ 12n log n. - Charles R Greathouse IV, Jul 01 2016

MATHEMATICA

Select[Range[13, 5000, 21], PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 04 2011 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(5000) | p mod 21 eq 13 ]; // Vincenzo Librandi, Apr 05 2011

(PARI) is(n)=isprime(n) && n%21==13 \\ Charles R Greathouse IV, Jul 01 2016

CROSSREFS

Cf. A000040, A124826.

Sequence in context: A297603 A094499 A242385 * A275879 A160554 A211388

Adjacent sequences:  A141891 A141892 A141893 * A141895 A141896 A141897

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Jul 11 2008

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 December 11 12:33 EST 2019. Contains 329916 sequences. (Running on oeis4.)