This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A163769 #14 Sep 08 2022 08:45:47 %S A163769 3,11,23,31,37,41,59,61,71,79,83,101,103,107,109,131,149,151,163,179, %T A163769 181,191,211,233,239,241,251,257,263,271,281,293,311,313,317,331,347, %U A163769 359,367,373,389,401,419,421,431,433,443,449,457,461,479,491,499,521 %N A163769 Primes p such that 2*p+3 is not prime. %C A163769 All those p appear in A144562. [Proof: since 2p+3 is odd and not prime, it can be written as a product of two odd numbers, 2p+3=(2k+1)*(2s+1), therefore p=2ks+k+s-1. - _R. J. Mathar_, Aug 06 2009] %H A163769 Vincenzo Librandi, <a href="/A163769/b163769.txt">Table of n, a(n) for n = 1..1000</a> %F A163769 A153238 INTERSECT A000040. - _R. J. Mathar_, Aug 05 2009 %F A163769 A000040 \ A023204. - _R. J. Mathar_, Aug 05 2009 %e A163769 3 is in the sequence because 2*3+3=9 is composite; 23 is in the sequence because 2*23+3=49 is composite. %t A163769 Select[Prime[Range[200]],!PrimeQ[2#+3]&] (* _Harvey P. Dale_, Feb 02 2012 *) %o A163769 (Magma) [p: p in PrimesUpTo(700) | not IsPrime(2*p+3)]; // _Vincenzo Librandi_, Apr 08 2013 %Y A163769 Cf. A144562. %K A163769 nonn,easy %O A163769 1,1 %A A163769 _Vincenzo Librandi_, Aug 04 2009 %E A163769 Entries checked - _R. J. Mathar_, Aug 06 2009