login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A243817 Primes p for which p - 4 and p^3 - 4 are primes. 3

%I #7 Jun 12 2014 13:26:12

%S 11,17,23,41,83,101,131,227,311,383,491,503,773,827,881,887,971,1097,

%T 1283,1301,1451,1493,1877,2141,2243,2273,2351,2687,2861,2957,3533,

%U 3881,3947,4007,4517,4643,5231,5237,5573,5741,6203,7211,7541,7883,7937,8741,9137,9551,10337,11447

%N Primes p for which p - 4 and p^3 - 4 are primes.

%C This is a subsequence of A046132: Larger member p+4 of cousin primes (p, p+4).

%H Abhiram R Devesh, <a href="/A243817/b243817.txt">Table of n, a(n) for n = 1..1000</a>

%e p = 11 is in this sequence because p - 4 = 7 (prime) and p^3 - 4 = 1327 (prime).

%e p = 17 is in this sequence because p - 4 = 13 (prime) and p^3 - 4 = 4909 (prime).

%o (Python)

%o import sympy.ntheory as snt

%o n=5

%o while n>1:

%o ....n1=n-4

%o ....n2=((n**3)-4)

%o ....##Check if n1 and n2 are also primes.

%o ....if snt.isprime(n1)== True and snt.isprime(n2)== True:

%o ........print(n, n1, n2)

%o ....n=snt.nextprime(n)

%Y Cf. A046132.

%K nonn,easy

%O 1,1

%A _Abhiram R Devesh_, Jun 11 2014

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 21:09 EDT 2024. Contains 371798 sequences. (Running on oeis4.)