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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A241267 Numbers n such that 4*n^2 + 4*n + 653 is not prime. 1
18, 19, 21, 24, 28, 33, 39, 46, 54, 60, 61, 62, 63, 65, 67, 72, 73, 75, 81, 82, 84, 85, 86, 93, 95, 96, 100, 101, 103, 104, 105, 109, 110, 111, 112, 117, 121, 122, 123, 125, 130, 137, 138, 139, 141, 142, 143, 144, 147, 152, 153, 154, 159, 160, 161, 165, 166 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

19 is in this sequence because 4*19^2 + 4*19 + 653 = 2173 = 41*53.

MATHEMATICA

Select[Range[0, 250], ! PrimeQ[4 #^2 + 4 # + 653] &]

PROG

(MAGMA) [n: n in [0..250] | not IsPrime(4*n^2+4*n+653)];

CROSSREFS

Complement of A188459.

Sequence in context: A018823 A025144 A326540 * A241848 A146331 A308894

Adjacent sequences:  A241264 A241265 A241266 * A241268 A241269 A241270

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Apr 20 2014

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 15 00:14 EDT 2019. Contains 328025 sequences. (Running on oeis4.)