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 A263282 #19 Sep 08 2022 08:46:14 %S A263282 63,65,88,98,102,133,157,163,185,193,198,203,208,210,233,245,250,262, %T A263282 310,340,380,387,413,437,457,462,473,478,483,493,507,508,515,530,585, %U A263282 600,627,635,640,647,658,662,677,718,742,765,772,793,795,830,847,857 %N A263282 Numbers n such that 6n is in A002822 but n is not. %C A263282 To use Dinculescu's terminology (see links): non-ranks n such that 6n is a twin-rank. %H A263282 Jason Kimberley, <a href="/A263282/b263282.txt">Table of n, a(n) for n = 1..27455</a> (equivalently, a(n) < 10^6). %H A263282 A. Dinculescu, <a href="http://dx.doi.org/10.2174/1874117701205010008">On Some Infinite Series Related to the Twin Primes</a>, The Open Mathematics Journal, 5 (2012), 8-14. %H A263282 A. Dinculescu, <a href="http://doi.org/10.9734/BJMCS/2013/4358">The Twin Primes Seen from a Different Perspective</a>, The British Journal of Mathematics & Computer Science, 3 (2013), Issue 4, 691-698. %e A263282 Take n = 63; then 6n = 378 and 36n = 2268; now 379, 2267, and 2269 are prime, but 377 = 13 x 29. %t A263282 s = Select[Range@ 5184, PrimeQ[6 # - 1] && PrimeQ[6 # + 1] &]; Select[s, IntegerQ[#/6] && ! MemberQ[s, #/6] &]/6 (* _Michael De Vlieger_, Oct 13 2015, after _N. J. A. Sloane_ at A002822 *) %o A263282 (Magma) IsInA2822:=func<n|IsPrime(6*n-1)and IsPrime(6*n+1)>; %o A263282 [n:n in[1..10^3]|not IsInA2822(n)and IsInA2822(6*n)]; %Y A263282 Cf. A002822. %K A263282 nonn,easy %O A263282 1,1 %A A263282 _Jason Kimberley_, Oct 13 2015