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 A153043 #27 Sep 08 2022 08:45:39 %S A153043 2,6,9,12,14,15,18,19,21,24,26,27,29,30,33,34,36,39,40,42,44,45,47,48, %T A153043 49,51,54,57,59,60,61,62,63,64,66,68,69,72,73,74,75,78,79,81,82,84,86, %U A153043 87,89,90,93,94,95,96,99,102,103,104,105,106,108,109,110 %N A153043 Numbers n > 1 such that 2*n-3 is not a prime. %C A153043 One more than the associated value in A104275. - _R. J. Mathar_, Jan 05 2011 %C A153043 2*A155705(m,n)-3 = (2n+1)*(2m+1) are nonprime: all A155705(.,.) are in this sequence. %C A153043 The terms after a(1) are the values of 2*h*k + k + h + 2, where h and k are positive integers. - _Vincenzo Librandi_, Jan 19 2013 %H A153043 Vincenzo Librandi, <a href="/A153043/b153043.txt">Table of n, a(n) for n = 1..1000</a> %t A153043 Select[Range[2,200], !PrimeQ[2*#-3]&] (* _Vladimir Joseph Stephan Orlovsky_, Feb 09 2012 *) %o A153043 (Magma) [n: n in [2..102] | not IsPrime(2*n-3)]; // _Bruno Berselli_, Mar 05 2011 %Y A153043 Cf. A098090, A104275, A153040, A155705. %K A153043 nonn,easy %O A153043 1,1 %A A153043 _Vincenzo Librandi_, Dec 17 2008