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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A114335 Numbers k such that k^2 + 1 and k^2 - 3 are both prime. 0
4, 10, 14, 20, 26, 40, 110, 124, 146, 206, 250, 326, 340, 350, 436, 440, 470, 634, 686, 704, 920, 1004, 1054, 1060, 1124, 1156, 1246, 1276, 1294, 1316, 1376, 1420, 1550, 1570, 1654, 1664, 1784, 1966, 1970, 2026, 2116, 2210, 2380, 2516, 2594, 2654, 2780 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is the intersection of A028873 and A005574; this sequence is also a subset of A090120 (n such that closest primes above and below n^2 differ by 4).

LINKS

Table of n, a(n) for n=1..47.

EXAMPLE

a(2)=10 since 10^2 + 1 = 101 and 10^2 - 3 = 97 are both prime.

PROG

(MAGMA) [n: n in [2..100000] |IsPrime(n^2+1) and IsPrime(n^2-3)] // Vincenzo Librandi, Nov 13 2010

CROSSREFS

Cf. A005574, A028873, A090120.

Sequence in context: A310421 A310422 A310423 * A302087 A099355 A161366

Adjacent sequences:  A114332 A114333 A114334 * A114336 A114337 A114338

KEYWORD

nonn

AUTHOR

John L. Drost, Feb 07 2006

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 October 16 15:49 EDT 2019. Contains 328101 sequences. (Running on oeis4.)