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!)
A306909 Primes p such that Omega(p + 1)^(p - 1) == 1 (mod p^2), where Omega is A001222. 0
2, 11, 1093, 3511, 20771, 534851, 1006003, 3152573 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(9) > 807795277 if it exists.

a(9) > 3.5*10^12 if it exists. - Giovanni Resta, Apr 09 2019

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

A001222(20772) = 5 and 5^(20771-1) == 1 (mod 20771^2), so 20771 is a term of the sequence.

MATHEMATICA

Select[Prime@ Range@ 230000, PowerMod[ PrimeOmega[# + 1], #-1, #^2] == 1 &] (* Giovanni Resta, Apr 09 2019 *)

PROG

(PARI) forprime(p=1, , if(Mod(bigomega(p+1), p^2)^(p-1)==1, print1(p, ", ")))

CROSSREFS

Cf. A001220, A001222, A260377, A267487.

Sequence in context: A293240 A157033 A011825 * A084673 A034388 A131316

Adjacent sequences:  A306906 A306907 A306908 * A306910 A306911 A306912

KEYWORD

nonn,hard,more

AUTHOR

Felix Fröhlich, Mar 16 2019

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 21 19:57 EDT 2020. Contains 337273 sequences. (Running on oeis4.)