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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A242260 Primes p such that p^2-2 is semiprime. 2
11, 17, 23, 31, 41, 53, 67, 73, 79, 83, 97, 109, 113, 149, 151, 163, 167, 197, 199, 229, 241, 251, 269, 281, 307, 331, 349, 379, 383, 389, 401, 433, 439, 457, 461, 463, 503, 547, 563, 593, 599, 601, 613, 617, 631, 643, 659, 661, 673, 691, 701, 709, 739, 769 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

filter:= t -> isprime(t) and numtheory:-bigomega(t^2-2)=2:

select(filter, [seq(i, i=3..10000, 2)]); # Robert Israel, Nov 17 2019

MATHEMATICA

Select[Table[Prime[k], {k, 1000}], PrimeOmega[#^2 - 2] == 2 &] (* M7*)

PROG

(PARI) s=[]; forprime(p=2, 1000, if(bigomega(p^2-2)==2, s=concat(s, p))); s \\ Colin Barker, May 10 2014

CROSSREFS

Subsequence of A219602. Cf. A001358.

Sequence in context: A158913 A066938 A219602 * A076812 A074207 A063638

Adjacent sequences:  A242257 A242258 A242259 * A242261 A242262 A242263

KEYWORD

nonn

AUTHOR

Zak Seidov, May 09 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 September 27 08:39 EDT 2021. Contains 347689 sequences. (Running on oeis4.)