# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a131356
Showing 1-1 of 1

%I A131356 #16 Jan 11 2024 20:40:22
%S A131356 2,5,14,17,23,26,41,56,59,65,80,101,104,122,128,131,161,194,212,230,
%T A131356 233,254,272,278,296,299,311,329,332,335,338,353,392,401,404,422,425,
%U A131356 464,479,500,509,527,551,563,584,587,608,626,629,635,644,656,665,668,677
%N A131356 Numbers k such that p1 = 10k+9 and p2 = p1+2 are twin primes.
%C A131356 All numbers k == 2 (mod 3).
%C A131356 All p1+1 are of form 30m with m=1, 2, 5, 6, 8, 9, 14, 19, 20, 22, 27, 34, 35, 41, 43, 44, 54, 65, 71, 77, 78, 85, 91, 93, 99, 100, 104, 110, 111, 112, 113, 118, 131, 134, 135, 141, 142, 155, 160, 167, 170, 176, 184, 188, 195, 196, 203, 209, 210, 212, 215, 219, 222, 223, 226, 229, 232, 245, 252, 253, 265, 267, 274, 281, 294, 299, 300, 308, 314, 321, 324, 331.
%C A131356 All p1 are of the form 6r-1 (=lesser of twin primes) with r=5m.
%H A131356 Robert Israel, <a href="/A131356/b131356.txt">Table of n, a(n) for n = 1..10000</a>
%p A131356 filter:= k -> isprime(10*k+9) and isprime(10*k+11):
%p A131356 select(filter, [seq(i,i=2..1000,3)]); # _Robert Israel_, Jan 11 2024
%t A131356 Select[Range[1200],PrimeQ[10#+9]&&PrimeQ[10#+11]&]
%Y A131356 Cf. A001359, A006512.
%K A131356 nonn
%O A131356 1,1
%A A131356 _Zak Seidov_, Sep 30 2007

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE