login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

p and 12*p+1 are both primes.
3

%I #12 Feb 04 2024 01:14:28

%S 3,5,13,19,23,29,31,59,61,71,73,83,89,101,103,139,149,191,199,223,229,

%T 233,269,271,281,293,311,379,383,401,409,433,463,479,503,523,569,601,

%U 631,643,661,691,719,751,761,773,811,829,839,863,883,929,953,1009,1013

%N p and 12*p+1 are both primes.

%H Harvey P. Dale, <a href="/A075704/b075704.txt">Table of n, a(n) for n = 0..1000</a>

%e 5 is a prime and 12*5+1=61 is also a prime. 13 and 12*13+1=157 are both primes...

%p ts_m_sophie_germain_pras := proc(n); if (isprime(n)='true' and isprime(12*n+1)='true') then RETURN(n); fi; end: seq(ts_m_sophie_germain_pras(i), i=1..2030);

%t Select[Prime[Range[300]],PrimeQ[12#+1]&] (* _Harvey P. Dale_, Feb 06 2012 *)

%Y Cf. A005384, A023212, A007693, A023228, A023237.

%K nonn

%O 0,1

%A _Jani Melik_, Oct 02 2002