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!)
A073102 Primes of the form 210n + 1. 20
211, 421, 631, 1051, 1471, 2311, 2521, 2731, 3361, 3571, 4201, 4621, 4831, 5881, 6091, 6301, 7351, 7561, 8191, 8821, 9241, 9661, 9871, 10501, 10711, 11131, 11551, 11971, 12391, 12601, 13441, 14071, 14281, 15121, 15331, 15541, 16381, 17011 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..38.

EXAMPLE

211 = 210*1 + 1 is prime; 1471 = 210*7 + 1 is prime.

MATHEMATICA

210*Flatten[Position[PrimeQ[210Range[100]+1], True]]+1

Select[1+210Range[100], PrimeQ] (* Ray Chandler, Apr 29 2010 *)

PROG

(MAGMA) [ a: n in [0..400] | IsPrime(a) where a is 210*n+1] // Vincenzo Librandi, Aug 08 2010

(PARI) select(x->((x % 210)==1), primes(3000)) \\ Michel Marcus, Jan 14 2018

CROSSREFS

Subsequence of A142076, A124826, and A132230.

Cf. A073085.

Sequence in context: A147156 A140535 A258332 * A076167 A217620 A289993

Adjacent sequences:  A073099 A073100 A073101 * A073103 A073104 A073105

KEYWORD

easy,nonn

AUTHOR

Zak Seidov Aug 24 2002

EXTENSIONS

Extended by Ray Chandler, Apr 29 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 December 16 04:22 EST 2019. Contains 330013 sequences. (Running on oeis4.)