login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A002971 Numbers k such that 4*k^2 + 25 is prime.
(Formerly M0587)
2
1, 2, 3, 4, 8, 9, 11, 12, 13, 14, 16, 17, 18, 21, 23, 26, 29, 34, 36, 37, 38, 47, 48, 49, 51, 53, 54, 56, 62, 63, 66, 67, 68, 69, 73, 74, 77, 79, 82, 83, 91, 99, 101, 102, 103, 107, 108, 114, 116, 118, 122, 131, 134, 141, 142, 147, 148, 151, 154, 156, 157, 158, 159, 164 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

E. Kogbetliantz and A. Krikorian, Handbook of First Complex Prime Numbers, Gordon and Breach, NY, 1971, p. 1.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

E. Kogbetliantz and A. Krikorian Handbook of First Complex Prime Numbers, Gordon and Breach, NY, 1971 [Annotated scans of a few pages]

MATHEMATICA

Select[Range[200], PrimeQ[4 #^2 + 25] &] (* Vincenzo Librandi, Mar 19 2014 *)

PROG

(MAGMA) [n: n in [0..600] |IsPrime(4*n^2+25)]; // Vincenzo Librandi, Nov 21 2010

(PARI) is(n)=isprime(4*n^2+25) \\ Charles R Greathouse IV, Jun 06 2017

CROSSREFS

Sequence in context: A246444 A045577 A111020 * A157318 A158031 A139461

Adjacent sequences:  A002968 A002969 A002970 * A002972 A002973 A002974

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

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 January 22 02:06 EST 2020. Contains 331133 sequences. (Running on oeis4.)